Difference between because and that’s why Because = gives the reason. That’s why = gives the result. Examples: I’m late because the bus was slow. The bus was slow. That’s why I’m late. She is happy because she got a new job. She got a new job. That’s why she is happy. We stayed home because it was raining. It was raining. That’s why we stayed home. Tip: Use because inside one sentence. Use that’s why to join two sentences.