彼の表情には恐怖が表れていた。

he; him; his; boyfriend

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

facial expression; countenance; look; appearance; expression (vocal, etc.)

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

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

fear; dread; dismay; terror; horror; scare; panic

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

to appear; to come in sight; to become visible; to come out; to embody; to materialize; to materialise; to be expressed (e.g. emotions); to become apparent (e.g. trends, effects)