Differences in grammar are relatively minor, and do not normally affect mutual intelligibility; these include: typically a lack of differentiation between adjectives and adverbs, employing the equivalent adjectives as adverbs "he ran quick"/"he ran quickly"; different use of some auxiliary verbs; formal (rather than notional) agreement with collective nouns; different preferences for the past forms of a few verbs (for example, AmE/BrE: "learned"/"learnt", "burned"/"burnt", "snuck/sneaked", "dove/dived") although the purportedly "British" forms can occasionally be seen in American English writing as well; different prepositions and adverbs in certain contexts (for example, AmE "in school," BrE "at school"); and whether or not a definite article is used, in very few cases (AmE "to the hospital", BrE "to hospital"; contrast, however, AmE "actress Elizabeth Taylor", BrE "the actress Elizabeth Taylor"). Often, these differences are a matter of relative preferences rather than absolute rules; and most are not stable since the two varieties are constantly influencing each other, and American English is not a standardized set of dialects.