雨が降れば家にいる。

rain

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

to descend; to go down; to come down; to be handed down (of an order, judgment, etc.); to pass (of time); to surrender; to capitulate; (often in neg. form) to be less than; to be inferior to; to have the runs; to have diarrhea

house; residence; dwelling; family; household; lineage; family name

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