彼はみんなが来てからやってきた。

he; him; his; boyfriend

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

all; everyone; everybody; everything

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

to come (spatially or temporally); to approach; to arrive; to come back; to do ... and come back; to come to be; to become; to get; to grow; to continue; to come from; to be caused by; to derive from; to come to (i.e. "when it comes to spinach ...")

from (e.g. time, place, numerical quantity); since; from (originator); by; because; since; out of (constituent, part); through (e.g. window, vestibule); after; since

to come along; to come around; to turn up; to arrive at the present; to get where one is; to have been doing something (for a period of time)