Who, Whom, That, Which

Subject vs object, and the difference between essential and extra information.

14 min · Read → Apply → Prove

Step 1 · Read

The relative-pronoun toolkit

Formal English still distinguishes who/whom. That vs which is about whether the clause is needed.

who = subject. The poet who writes at night. (who writes = she writes)
whom = object. The poet to whom we spoke. (we spoke to her → whom)
Trick: recast with he/him. If him fits, whom fits.
that / which (restrictive vs nonrestrictive): The book that I lost was new. (needed to identify). The book, which I lost, was new. (extra, commas). American school style often prefers that for essential clauses about things.

Step 2 · Apply

A short exercise to turn what you learned into skill.

Fill the blank with who or whom: “To _____ did the keeper give the key?” Then write the full sentence.

to him → whom. The preposition to takes an object.

Step 3 · Prove

Pass with 70% or higher to complete this lesson.