So what happened?
1	So	so	ADV	RB	_	3	advmod	3:advmod	_
2	what	what	PRON	WP	PronType=Int	3	nsubj	3:nsubj	_
3	happened	happen	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	0:root	SpaceAfter=No
4	?	?	PUNCT	.	_	3	punct	3:punct	_
