Which sentences contain a restrictive clause?

1. we fed the kittens that we found in the shed.
2. my grandmother, who was growing crankier by the day, scolded him harshly.
3. this is the house that i grew up in.
4. our teacher, who was always ready to share in a good joke, laughed with us.

@beanthemachine

Restrictive clauses are essential for the meaning of a sentence and are never separated from the rest of the sentence using commas, unlike the nonrestrictive ones. So, having that in mind, the sentences that contain a restrictive clause are 1 and 3. In both of these sentences, restrictive clauses (in 1, that we found in the shed, and in 3. that I grew up in) are important to understand the whole sentence and cannot be deleted. In 2 and 4, however, the clauses inside the commas are not relevant for the meaning of the whole sentence.