(ROOT (SQ (VBP Have) (NP (PRP you)) (ADVP (RB ever)) (VP (VBN heard) (S (NP (NN someone)) (VP (VB use) (NP (DT the) (NN phrase)) (`` ``) (PP (ADVP (RB once)) (IN in) (NP (DT a) (JJ blue) (NN moon))) ('' '')))) (. ?)))
Have you ever heard someone use the phrase "once in a blue moon"?
aux
Mood=Ind|Number=Sing|Person=2|Tense=Pres|VerbForm=Fin
have
Have
AUX
VBP
nsubj
Case=Nom|Person=2|PronType=Prs
you
you
PRON
PRP
advmod
ever
ever
ADV
RB
root
Tense=Past|VerbForm=Part
hear
heard
VERB
VBN
nsubj
Number=Sing|PronType=Ind
someone
someone
PRON
NN
ccomp
VerbForm=Inf
use
use
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
phrase
phrase
NOUN
NN
punct
``
``
PUNCT
``
parataxis
NumType=Mult
once
once
ADV
RB
case
in
in
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
blue
blue
ADJ
JJ
obl
Number=Sing
moon
moon
NOUN
NN
punct
''
''
PUNCT
''
punct
?
?
PUNCT
.
(ROOT (S (NP (NNS People)) (VP (VBP use) (NP (DT this) (NN expression)) (S (VP (TO to) (VP (VB describe) (NP (NP (NN something)) (SBAR (WHNP (WDT that)) (S (NP (PRP they)) (VP (VBP do) (RB not) (VP (VB do) (ADVP (RB very) (RB often))))))))))) (. .)))
People use this expression to describe something that they do not do very often.
nsubj
Number=Plur
person
People
NOUN
NNS
root
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
use
use
VERB
VBP
det
Number=Sing|PronType=Dem
this
this
DET
DT
obj
Number=Sing
expression
expression
NOUN
NN
mark
to
to
PART
TO
advcl
VerbForm=Inf
describe
describe
VERB
VB
obj
Number=Sing|PronType=Ind
something
something
PRON
NN
obj
PronType=Rel
that
that
PRON
WDT
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
aux
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
do
do
AUX
VBP
advmod
not
not
PART
RB
acl:relcl
VerbForm=Inf
do
do
VERB
VB
advmod
very
very
ADV
RB
advmod
often
often
ADV
RB
punct
.
.
PUNCT
.
(ROOT (S (PP (IN For) (NP (NN example))) (, ,) (NP (NN someone)) (VP (MD might) (VP (VB say) (SBAR (IN that) (S (NP (PRP he)) (VP (VP (VBZ tries) (S (VP (TO to) (VP (VB avoid) (S (VP (VBG eating) (NP (NNS sweets))))))) (SBAR (IN because) (S (NP (PRP they)) (VP (VBP are) (ADJP (JJ unhealthy)))))) (, ,) (CC but) (VP (MD will) (VP (VB eat) (NP (NN chocolate)) (`` ``) (PP (ADVP (RB once)) (IN in) (NP (DT a) (JJ blue) (NN moon)))))))))) ('' '') (. .)))
For example, someone might say that he tries to avoid eating sweets because they are unhealthy, but will eat chocolate "once in a blue moon".
case
for
For
ADP
IN
obl
Number=Sing
example
example
NOUN
NN
punct
,
,
PUNCT
,
nsubj
Number=Sing|PronType=Ind
someone
someone
PRON
NN
aux
VerbForm=Fin
might
might
AUX
MD
root
VerbForm=Inf
say
say
VERB
VB
mark
that
that
SCONJ
IN
nsubj
Case=Nom|Gender=Masc|Number=Sing|Person=3|PronType=Prs
he
he
PRON
PRP
ccomp
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
try
tries
VERB
VBZ
mark
to
to
PART
TO
xcomp
VerbForm=Inf
avoid
avoid
VERB
VB
xcomp
VerbForm=Ger
eat
eating
VERB
VBG
obj
Number=Plur
sweet
sweets
NOUN
NNS
mark
because
because
SCONJ
IN
nsubj
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
cop
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
be
are
AUX
VBP
advcl
Degree=Pos
unhealthy
unhealthy
ADJ
JJ
punct
,
,
PUNCT
,
cc
but
but
CCONJ
CC
aux
VerbForm=Fin
will
will
AUX
MD
conj
VerbForm=Inf
eat
eat
VERB
VB
obj
Number=Sing
chocolate
chocolate
NOUN
NN
punct
``
``
PUNCT
``
advmod
NumType=Mult
once
once
ADV
RB
case
in
in
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
blue
blue
ADJ
JJ
obl
Number=Sing
moon
moon
NOUN
NN
punct
''
''
PUNCT
''
punct
.
.
PUNCT
.
(ROOT (S (CC Or) (NP (NP (NN someone)) (SBAR (WHNP (WP who)) (S (VP (VBZ does) (RB not) (ADVP (RB usually)) (VP (VB like) (S (VP (TO to) (VP (VB go) (PP (IN to) (NP (DT the) (NN beach))))))))))) (VP (MD might) (VP (VB say) (`` ``) (S (NP (PRP I)) (VP (VBP visit) (NP (DT the) (NN shore)) (ADVP (RB once) (PP (IN in) (NP (DT a) (NN moon)))))))) (. .) ('' '')))
Or someone who does not usually like to go to the beach might say "I visit the shore once in a moon."
cc
or
Or
CCONJ
CC
nsubj
Number=Sing|PronType=Ind
someone
someone
PRON
NN
nsubj
PronType=Rel
who
who
PRON
WP
aux
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
do
does
AUX
VBZ
advmod
not
not
PART
RB
advmod
usually
usually
ADV
RB
acl:relcl
VerbForm=Inf
like
like
VERB
VB
mark
to
to
PART
TO
xcomp
VerbForm=Inf
go
go
VERB
VB
case
to
to
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
beach
beach
NOUN
NN
aux
VerbForm=Fin
might
might
AUX
MD
root
VerbForm=Inf
say
say
VERB
VB
punct
``
``
PUNCT
``
nsubj
Case=Nom|Number=Sing|Person=1|PronType=Prs
I
I
PRON
PRP
ccomp
Mood=Ind|Number=Sing|Person=1|Tense=Pres|VerbForm=Fin
visit
visit
VERB
VBP
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
shore
shore
NOUN
NN
advmod
NumType=Mult
once
once
ADV
RB
case
in
in
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
obl
Number=Sing
moon
moon
NOUN
NN
punct
.
.
PUNCT
.
punct
''
''
PUNCT
''
(ROOT (S (SBAR (IN While) (S (NP (JJ many) (NNS people)) (VP (VBP use) (NP (DT this) (NN phrase))))) (, ,) (NP (RB not) (NN everyone)) (VP (VBZ knows) (NP (NP (DT the) (NN meaning)) (PP (IN behind) (NP (PRP it))))) (. .)))
While many people use this phrase, not everyone knows the meaning behind it.
mark
while
While
SCONJ
IN
amod
Degree=Pos
many
many
ADJ
JJ
nsubj
Number=Plur
person
people
NOUN
NNS
advcl
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
use
use
VERB
VBP
det
Number=Sing|PronType=Dem
this
this
DET
DT
obj
Number=Sing
phrase
phrase
NOUN
NN
punct
,
,
PUNCT
,
advmod
not
not
PART
RB
nsubj
Number=Sing|PronType=Tot
everyone
everyone
PRON
NN
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
know
knows
VERB
VBZ
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
meaning
meaning
NOUN
NN
case
behind
behind
ADP
IN
nmod
Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (NP (DT The) (JJ first) (NN thing)) (SBAR (S (VP (TO to) (VP (VB know)))))) (VP (VBZ is) (SBAR (IN that) (S (NP (NP (DT the) (NN moon)) (NP (PRP itself))) (VP (VBZ is) (ADVP (RB never)) (ADJP (RB really) (JJ blue)))))) (. .)))
The first thing to know is that the moon itself is never really blue.
det
Definite=Def|PronType=Art
the
The
DET
DT
amod
Degree=Pos|NumType=Ord
first
first
ADJ
JJ
nsubj:outer
Number=Sing
thing
thing
NOUN
NN
mark
to
to
PART
TO
acl
VerbForm=Inf
know
know
VERB
VB
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
mark
that
that
SCONJ
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nsubj
Number=Sing
moon
moon
NOUN
NN
nmod:npmod
Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Emp|Reflex=Yes
itself
itself
PRON
PRP
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
advmod
never
never
ADV
RB
advmod
really
really
ADV
RB
root
Degree=Pos
blue
blue
ADJ
JJ
punct
.
.
PUNCT
.
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (RB just) (DT an) (NN expression))) (. .)))
This is just an expression.
nsubj
Number=Sing|PronType=Dem
this
This
PRON
DT
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
advmod
just
just
ADV
RB
det
Definite=Ind|PronType=Art
a
an
DET
DT
root
Number=Sing
expression
expression
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (PP (IN In) (NP (NN fact))) (, ,) (NP (DT the) (NN phrase) (`` ``) (JJ blue) (NN moon) ('' '')) (VP (VBZ has) (S (VP (TO to) (VP (VB do) (PP (IN with) (NP (NP (NP (DT the) (NN shape)) (PP (IN of) (NP (DT the) (NN moon)))) (, ,) (RB not) (NP (DT the) (NN color)))))))) (. .)))
In fact, the phrase "blue moon" has to do with the shape of the moon, not the color.
case
in
In
ADP
IN
obl
Number=Sing
fact
fact
NOUN
NN
punct
,
,
PUNCT
,
det
Definite=Def|PronType=Art
the
the
DET
DT
nsubj
Number=Sing
phrase
phrase
NOUN
NN
punct
``
``
PUNCT
``
amod
Degree=Pos
blue
blue
ADJ
JJ
appos
Number=Sing
moon
moon
NOUN
NN
punct
''
''
PUNCT
''
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
have
has
VERB
VBZ
mark
to
to
PART
TO
xcomp
VerbForm=Inf
do
do
VERB
VB
case
with
with
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
shape
shape
NOUN
NN
case
of
of
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
moon
moon
NOUN
NN
punct
,
,
PUNCT
,
advmod
not
not
PART
RB
det
Definite=Def|PronType=Art
the
the
DET
DT
conj
Number=Sing
color
color
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (SBAR (IN As) (S (NP (DT the) (NN moon)) (VP (VBZ travels) (PP (IN around) (NP (DT the) (NN earth)))))) (, ,) (NP (PRP it)) (VP (VBZ appears) (S (VP (TO to) (VP (VB change) (NP (NN shape)))))) (. .)))
As the moon travels around the earth, it appears to change shape.
mark
as
As
SCONJ
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nsubj
Number=Sing
moon
moon
NOUN
NN
advcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
travel
travels
VERB
VBZ
case
around
around
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
earth
earth
NOUN
NN
punct
,
,
PUNCT
,
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
appear
appears
VERB
VBZ
mark
to
to
PART
TO
xcomp
VerbForm=Inf
change
change
VERB
VB
obj
Number=Sing
shape
shape
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (PRP We)) (VP (VBP associate) (NP (NNS names)) (PP (IN with) (NP (NP (JJ certain) (NNS shapes)) (PP (IN of) (NP (DT the) (NN moon)))))) (. .)))
We associate names with certain shapes of the moon.
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
We
PRON
PRP
root
Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin
associate
associate
VERB
VBP
obj
Number=Plur
name
names
NOUN
NNS
case
with
with
ADP
IN
amod
Degree=Pos
certain
certain
ADJ
JJ
nmod
Number=Plur
shape
shapes
NOUN
NNS
case
of
of
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
moon
moon
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (PP (IN For) (NP (NN example))) (, ,) (SBAR (WHADVP (WRB when)) (S (NP (PRP we)) (VP (MD can) (VP (VB see) (NP (NP (DT a) (JJ small) (NN part)) (PP (IN of) (NP (DT the) (NN moon)))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (S (NP (DT a) (NN crescent) (NN moon))))) (. .)))
For example, when we can see a small part of the moon, it is called a crescent moon.
case
for
For
ADP
IN
obl
Number=Sing
example
example
NOUN
NN
punct
,
,
PUNCT
,
advmod
PronType=Int
when
when
ADV
WRB
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
advcl
VerbForm=Inf
see
see
VERB
VB
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
small
small
ADJ
JJ
obj
Number=Sing
part
part
NOUN
NN
case
of
of
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
moon
moon
NOUN
NN
punct
,
,
PUNCT
,
nsubj:pass
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux:pass
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Tense=Past|VerbForm=Part|Voice=Pass
call
called
VERB
VBN
det
Definite=Ind|PronType=Art
a
a
DET
DT
compound
Number=Sing
crescent
crescent
NOUN
NN
obj
Number=Sing
moon
moon
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (DT A) (NN crescent)) (VP (VBZ is) (NP (NP (DT a) (NN shape)) (SBAR (WHNP (WDT that)) (S (VP (VBZ looks) (PP (IN like) (NP (NP (DT the) (NN tip)) (PP (IN of) (NP (DT a) (NN fingernail)))))))))) (. .)))
A crescent is a shape that looks like the tip of a fingernail.
det
Definite=Ind|PronType=Art
a
A
DET
DT
nsubj
Number=Sing
crescent
crescent
NOUN
NN
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
det
Definite=Ind|PronType=Art
a
a
DET
DT
root
Number=Sing
shape
shape
NOUN
NN
nsubj
PronType=Rel
that
that
PRON
WDT
acl:relcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
look
looks
VERB
VBZ
case
like
like
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
tip
tip
NOUN
NN
case
of
of
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
nmod
Number=Sing
fingernail
fingernail
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (PRP we)) (VP (MD can) (RB not) (VP (VB see) (NP (DT the) (NN moon)) (ADVP (IN at) (DT all)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (S (NP (DT a) (JJ new) (NN moon))))) (. .)))
When we cannot see the moon at all, it is called a new moon.
advmod
PronType=Int
when
When
ADV
WRB
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
advmod
not
not
PART
RB
advcl
VerbForm=Inf
see
see
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
moon
moon
NOUN
NN
case
at
at
ADP
IN
obl
all
all
DET
DT
punct
,
,
PUNCT
,
nsubj:pass
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux:pass
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Tense=Past|VerbForm=Part|Voice=Pass
call
called
VERB
VBN
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
new
new
ADJ
JJ
obj
Number=Sing
moon
moon
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (PRP we)) (VP (MD can) (VP (VB see) (NP (DT the) (JJ whole) (NN moon)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (S (NP (DT a) (JJ full) (NN moon))))) (. .)))
When we can see the whole moon, it is called a full moon.
advmod
PronType=Int
when
When
ADV
WRB
nsubj
Case=Nom|Number=Plur|Person=1|PronType=Prs
we
we
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
advcl
VerbForm=Inf
see
see
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
whole
whole
ADJ
JJ
obj
Number=Sing
moon
moon
NOUN
NN
punct
,
,
PUNCT
,
nsubj:pass
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux:pass
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Tense=Past|VerbForm=Part|Voice=Pass
call
called
VERB
VBN
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
full
full
ADJ
JJ
obj
Number=Sing
moon
moon
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (ADVP (RB Usually)) (, ,) (NP (EX there)) (VP (VBZ is) (NP (QP (RB only) (CD one)) (JJ full) (NN moon)) (NP (DT every) (NN month))) (. .)))
Usually, there is only one full moon every month.
advmod
usually
Usually
ADV
RB
punct
,
,
PUNCT
,
expl
there
there
PRON
EX
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
VERB
VBZ
advmod
only
only
ADV
RB
nummod
NumForm=Word|NumType=Card
one
one
NUM
CD
amod
Degree=Pos
full
full
ADJ
JJ
nsubj
Number=Sing
moon
moon
NOUN
NN
det
PronType=Tot
every
every
DET
DT
obl:tmod
Number=Sing
month
month
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (ADVP (RB Sometimes)) (, ,) (ADVP (RB however)) (, ,) (NP (EX there)) (VP (MD will) (VP (VB be) (NP (CD two) (JJ full) (NNS moons)) (PP (IN in) (NP (CD one) (NN month))))) (. .)))
Sometimes, however, there will be two full moons in one month.
advmod
sometimes
Sometimes
ADV
RB
punct
,
,
PUNCT
,
advmod
however
however
ADV
RB
punct
,
,
PUNCT
,
expl
there
there
PRON
EX
aux
VerbForm=Fin
will
will
AUX
MD
root
VerbForm=Inf
be
be
VERB
VB
nummod
NumForm=Word|NumType=Card
two
two
NUM
CD
amod
Degree=Pos
full
full
ADJ
JJ
nsubj
Number=Plur
moon
moons
NOUN
NNS
case
in
in
ADP
IN
nummod
NumForm=Word|NumType=Card
one
one
NUM
CD
obl
Number=Sing
month
month
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT this)) (VP (VBZ happens)))) (, ,) (NP (DT the) (JJ second) (JJ full) (NN moon)) (VP (VBZ is) (VP (VBN called) (S (NP (DT a) (`` ``) (JJ blue) (NN moon) ('' ''))))) (. .)))
When this happens, the second full moon is called a "blue moon".
advmod
PronType=Int
when
When
ADV
WRB
nsubj
Number=Sing|PronType=Dem
this
this
PRON
DT
advcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
happen
happens
VERB
VBZ
punct
,
,
PUNCT
,
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos|NumType=Ord
second
second
ADJ
JJ
amod
Degree=Pos
full
full
ADJ
JJ
nsubj:pass
Number=Sing
moon
moon
NOUN
NN
aux:pass
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Tense=Past|VerbForm=Part|Voice=Pass
call
called
VERB
VBN
det
Definite=Ind|PronType=Art
a
a
DET
DT
punct
``
``
PUNCT
``
amod
Degree=Pos
blue
blue
ADJ
JJ
obj
Number=Sing
moon
moon
NOUN
NN
punct
''
''
PUNCT
''
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (PP (IN Over) (NP (DT the) (JJ next) (CD 20) (NNS years))) (, ,) (NP (EX there)) (VP (MD will) (ADVP (RB only)) (VP (VB be) (NP (CD 15) (JJ blue) (NNS moons)))) (. .)))
Over the next 20 years, there will only be 15 blue moons.
case
over
Over
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
next
next
ADJ
JJ
nummod
NumForm=Digit|NumType=Card
20
20
NUM
CD
obl
Number=Plur
year
years
NOUN
NNS
punct
,
,
PUNCT
,
expl
there
there
PRON
EX
aux
VerbForm=Fin
will
will
AUX
MD
advmod
only
only
ADV
RB
root
VerbForm=Inf
be
be
VERB
VB
nummod
NumForm=Digit|NumType=Card
15
15
NUM
CD
amod
Degree=Pos
blue
blue
ADJ
JJ
nsubj
Number=Plur
moon
moons
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (SBAR (IN As) (S (NP (PRP you)) (VP (MD can) (VP (VB see))))) (, ,) (NP (DT a) (JJ blue) (NN moon)) (VP (VBZ is) (NP (DT a) (ADJP (RB very) (JJ rare)) (NN event))) (. .)))
As you can see, a blue moon is a very rare event.
mark
as
As
SCONJ
IN
nsubj
Case=Nom|Person=2|PronType=Prs
you
you
PRON
PRP
aux
VerbForm=Fin
can
can
AUX
MD
advcl
VerbForm=Inf
see
see
VERB
VB
punct
,
,
PUNCT
,
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
blue
blue
ADJ
JJ
nsubj
Number=Sing
moon
moon
NOUN
NN
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
det
Definite=Ind|PronType=Art
a
a
DET
DT
advmod
very
very
ADV
RB
amod
Degree=Pos
rare
rare
ADJ
JJ
root
Number=Sing
event
event
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (DT This) (NN fact)) (VP (VBZ has) (VP (VBN led) (NP (NNS people)) (S (VP (TO to) (VP (VB use) (NP (DT the) (NN expression)) (`` ``) (PP (ADVP (RB once)) (IN in) (NP (DT a) (JJ blue) (NN moon))) ('' '') (PP (IN to) (NP (NP (JJ other) (ADJP (RB very) (JJ rare)) (NNS events)) (PP (IN in) (NP (PRP$ their) (NNS lives)))))))))) (. .)))
This fact has led people to use the expression "once in a blue moon" to other very rare events in their lives.
det
Number=Sing|PronType=Dem
this
This
DET
DT
nsubj
Number=Sing
fact
fact
NOUN
NN
aux
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
have
has
AUX
VBZ
root
Tense=Past|VerbForm=Part
lead
led
VERB
VBN
obj
Number=Plur
person
people
NOUN
NNS
mark
to
to
PART
TO
xcomp
VerbForm=Inf
use
use
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
expression
expression
NOUN
NN
punct
``
``
PUNCT
``
appos
NumType=Mult
once
once
ADV
RB
case
in
in
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
blue
blue
ADJ
JJ
obl
Number=Sing
moon
moon
NOUN
NN
punct
''
''
PUNCT
''
case
to
to
ADP
IN
amod
Degree=Pos
other
other
ADJ
JJ
advmod
very
very
ADV
RB
amod
Degree=Pos
rare
rare
ADJ
JJ
obl
Number=Plur
event
events
NOUN
NNS
case
in
in
ADP
IN
nmod:poss
Case=Gen|Number=Plur|Person=3|Poss=Yes|PronType=Prs
their
their
PRON
PRP$
nmod
Number=Plur
life
lives
NOUN
NNS
punct
.
.
PUNCT
.
Have you ever heard someone use the phrase "once in a blue moon"? People use this expression to describe something that they do not do very often. For example, someone might say that he tries to avoid eating sweets because they are unhealthy, but will eat chocolate "once in a blue moon". Or someone who does not usually like to go to the beach might say "I visit the shore once in a moon." While many people use this phrase, not everyone knows the meaning behind it.  The first thing to know is that the moon itself is never really blue. This is just an expression. In fact, the phrase "blue moon" has to do with the shape of the moon, not the color.  As the moon travels around the earth, it appears to change shape. We associate names with certain shapes of the moon. For example, when we can see a small part of the moon, it is called a crescent moon. A crescent is a shape that looks like the tip of a fingernail. When we cannot see the moon at all, it is called a new moon. When we can see the whole moon, it is called a full moon. Usually, there is only one full moon every month. Sometimes, however, there will be two full moons in one month. When this happens, the second full moon is called a "blue moon".  Over the next 20 years, there will only be 15 blue moons. As you can see, a blue moon is a very rare event. This fact has led people to use the expression "once in a blue moon" to other very rare events in their lives.