on Writing Forward: There’s a lot of confusion about that and which. These two words are often used interchangeably, even though they’re not necessarily interchangeable. Historically, that and which may have carried the same meaning, and some English dialects may allow for that and which to be swapped without affecting the meaning of a sentence. […]

Grammar Rules: That and Which – by Melissa Donovan… — Chris The Story Reading Ape’s Blog