The correct tenses pairs for main and sub clauses

Question

A: The goods that he bought yesterday are a car, a television, and a bunch of candies.

B: The goods that he bought yesterday were a car, a television, and a bunch of candies.

Which one is the correct pair of tenses?

Answer 1

Since yesterday is in the past, you would generally use were, regardless of whether "goods" is a generic plural or not.

See this definition of "were" from Merriam-Webster:

past tense second-person singular, past tense plural, and past subjunctive of be

In your case, "yesterday" indicates that it's likely past tense plural. Even if what you wanted was past-tense singular, you wouldn't say are, you would say was, per this definition of "was" from Merriam-Webster:

past tense first- and third-person singular of be

But as you can tell, it would sound unnatural to say

The goods was

So we can conclude that "the goods" should be treated as plural.

The one caveat is that the sentence could refer to goods that continue to exist now, and refer to the state that they're in now. If you want to specifically refer to their present condition, you would use "are" as present tense plural.

The apples that he bought yesterday are turning brown.

However, unless you are specifically adding context relevant to the present state of the goods, you would assume past tense because of the word yesterday.

The apples that he bought yesterday were a combination of McIntosh and Red Delicious.

In your case, because there is no additional context relevant to present tense, you want to use were.

The goods that he bought yesterday were a car, a television, and a bunch of candies.