列車が止まるまでドアを開けてはいけません。

train (ordinary)

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

to stop (moving); to come to a stop; to stop (doing, working, being supplied); to come to a halt; to cease; to be stopped; to be suspended; to alight; to perch on

until (a time); till; to; up to; to (a place); as far as; to (an extent); up to; so far as; even; only; merely

door (Western-style)

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to open; to bare; to expose; to stretch

if ... then; when; and; why don't you...?; the more (one does something); because; since