I wrote the following sentence in an essay: "My idea was that, since A is B, B might be A". However, word count matters in this essay, so I'd like to know if the "that" is optional in this sentence. More specifically, I want to know if "My idea was, since A is B, B might be A." is also correct.

  • It basically functions as an oral colon: My idea was: 'Since A is B, B might be A', introducing a tensed clause and identifying it with the subject. Since that is a complementizer, introducing and identifying clauses is its primary function; complementizer that is optional everywhere, except at the beginning of a sentence, where it's necessary to identify the clause as subordinate: That you forgot is no excuse, but not *You forgot is no excuse. Sep 20 '18 at 22:45

Yes, it is optional. 'That' is a demonstrative pronoun that has evolved to also work as a relativizer ("the girl that kissed me"; "the boy [that] she kissed") or a complementizer ("I know [that] she kissed him.")


My idea was that [since A is B, B might be A.]

Yes, the subordinator "that" is optional here, where it introduces the bracketed declarative content clause.

But note that in such clauses, "that" is sometimes inadmissible, for example when it is complement to a preposition like "before", as in in *"I left before that he arrived".

And sometimes it is obligatory, for example when the content clause is subject of the matrix clause, as in "That I need help is clear". Elsewhere it is generally optional, though it is more likely to be omitted in informal than formal style, and after short and common verbs.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.