از، به، در، با

In از مدرسه به خانه آمدم, the first phrase gives the source and the second gives the destination. Keep both phrases intact rather than treating their nouns as two direct objects.

با can also introduce an instrument, as in با قلم نوشتم. Learn the full predicate’s complement pattern: به سارا کمک کردم uses به with کمک کردن.

Everyday Iranian often uses تو or توی for a location corresponding to written در. In some natural clauses a location or destination appears without a preposition. Recognize those actual spoken patterns; do not assume a missing preposition is always an error.

A known referent inside a prepositional complement does not automatically require را. The object marker and the preposition express different grammatical relations.