My mother and ____ went shopping for clothes yesterday.

In the sentence "My mother and ____ went shopping for clothes yesterday," the correct choice is "I." This is because when the pronoun is part of the subject of a sentence, it should be in the subjective case, which is "I" in this instance.

When constructing sentences, the subject pronoun is used to indicate who is performing the action. Here, the mother and the speaker are performing the action of going shopping. Therefore, "I" is the appropriate pronoun to use to maintain grammatical correctness. A clearer understanding of this can be derived from considering the sentence without the mother: "I went shopping for clothes yesterday," which confirms the use of "I" as the subject.

Using "me," "myself," or "us" in this context would be incorrect because they do not serve as subject pronouns. "Me" is an object pronoun, "myself" is a reflexive pronoun, and "us" is a plural object pronoun, which do not fit the grammatical requirements of this sentence structure.