彼がそこにいるかもしれない。

he; him; his; boyfriend

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

there (place relatively near listener); there (place just mentioned); that place; then (of some incident just spoken of); that (of point just raised); you

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

to need; to want

may; might; perhaps; may be; possibly

to become known; to come to light; to be discovered; to be known; to be understood; to obviously not amount to much; to seem trivial; to be evident; to be obvious; to go without saying; to be very intense (worry, hope, etc.); to be extremely severe