Exercise 1-54: Intonation and Pronunciation of "That"

That is a special case because it serves three different grammatical functions.

The relative pronoun and the conjunction are reducible.

The demonstrative pronoun cannot be reduced to a schwa sound.

It must stay .

Relative Pronoun

The car that she ordered is red.

Conjunction

He said that he liked it.

Demonstrative

Why did you do that?

Combination

I know that he'll read that book that I told you about.