These are relative clauses and it depends on which relative pronoun you use as to whether you need a preposition or not. to which = where The garage to which I always go for repairs was closed today. [more formal] The garage which/that I always go to for repairs was closed today, [less formal] The garage I always go to for repairs was closed today, [even less formal] in which = where That's the church in which we got married. That's the church [that/which] we got married in. That's the church where we got married.

1. “The garage that I always go to for repairs was closed today.” The verb “go” typically requires “to” when you're specifying a destination with “that.” Also, the sentence is emphasizing the action of going to the garage, which is why “to” is necessary. The emphasis is on the movement toward the destination rather than the destination itself. 2. “The garage where I always go for repairs was closed today.” Here, “where” refers to the location of the garage itself, emphasizing the destination. The word “where” inherently means “the place at which” or “the place to which.” Therefore, the sentence naturally implies that the garage is the destination, without needing the preposition “to.” The focus is on the location or destination itself. It's the same reason why you can ask “Where are you going?” without needing to say “Where are you going to?”