Here are a few questions about pronouns submitted by readers, along with my responses.
1. This sentence does not sound correct to me, and it was spoken by a high school English teacher: “She wanted my other sister and I to focus on it.” Is it right?
Your instinct is spot-on: Remove “my other sister and,” and what are you left with? “She wanted I to focus on it.” Therefore, me is the appropriate form. (You wouldn’t write or say, “This sentence does not sound correct to I.”) I would be correct only if it were the subject, or part of the subject, of the sentence, as in “My other sister and I will focus on it.”
2. If I am showing someone photographs, would I say, “This is me in a canoe,” or is it I?
In your sentence, the personal pronoun is a predicate nominative — it renames the subject, this — so (in strictly formal writing, at least) it should be in the subjective form: “This is I in a canoe.” Most of us don’t talk or write that way, however, even in many formal contexts.
3. In your phrase “dysphemism assigns a mildly or scathingly pejorative term to a concept or person that may be considered neutral or positive,” is it correct to have that refer to a concept and a person?
A person may be referred to as either a who or a that, though the former relative pronoun is preferred, but if a reference to a person is linked to a reference to a thing, as here, the pronoun must be that. To sidestep the issue, I could have written, “dysphemism assigns a mildly or scathingly pejorative term to a concept that, or a person who, may be considered neutral or positive.”