"To which" is a phrase often used to connect two ideas together, but it can become repetitive when used repeatedly in writing or speech. Fortunately, there are several synonyms for this phrase that can add variety and clarity to your communication. These include expressions such as "to whom," "for which," "with which," "by which," and "under which." Each of these phrases can be used in place of "to which" depending on the context of your sentence. Experiment with these synonyms in your writing or speech to find the phrase that works best for conveying your meaning.