どれに乗ったらよいか彼女に教えなさい。

which (of three or more); whichever; any; well; now; let me see

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 get on (train, plane, bus, ship, etc.); to get in; to board; to take; to embark; to get on (e.g. a footstool); to step on; to jump on; to sit on; to mount; to reach; to go over; to pass; to follow; to stay (on track); to go with (the times, etc.); to take part; to participate; to join; to get into the swing (and sing, dance, etc.); to be deceived; to be taken in; to be carried; to be spread; to be scattered; to stick; to attach; to take; to go on

good; excellent; fine; nice; pleasant; agreeable; sufficient (can be used to turn down an offer); ready; prepared; profitable (e.g. deal, business offer, etc.); beneficial; OK

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way

she; her; her; girlfriend; sweetheart

to teach; to inform; to instruct

to do