彼はびっくりするほどのアクロバットができる。

he; him; his; boyfriend

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

to be surprised; to be amazed; to be frightened; to be astonished; to get startled; to jump; surprise (e.g. surprise party)

degree; extent; bounds; limit; indicates approx. amount or maximum; upper limit

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

acrobat; acrobatics

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to be able (in a position) to do; to be up to the task; to be ready; to be completed; to be made; to be built; to be good at; to be permitted (to do); to become intimate; to take up (with somebody); to grow; to be raised; to become pregnant