Weren't is the contraction of “were not.” It's what you say when describing something that didn't happen in the past or wasn't true about one or more people or things.

You use weren't when talking about more than one person or thing: “The cookies weren't ready yet” or “We weren't expecting rain today.” You also use it with the word you, even when talking to just one person: “You weren't at practice yesterday.”

The word combines were (the past tense of are) with not, and the apostrophe shows where letters got squeezed out.

One tricky spot: people sometimes confuse weren't with wasn't. Use weren't for plural subjects (“They weren't home”) and wasn't for singular subjects (“He wasn't home”). However, you always say “you weren't,” never “you wasn't,” even when talking to one person.

You might hear weren't in questions too: “Weren't you scared?” or “Weren't those your books?”