Here are five basic functions the word “that” may perform in a sentence.
1. Subordinating conjunction, introducing a relative/adjectival clause
- Many bloggers that I know are wonderful people.
- That’s the bird that flew into our office.
2. Subordinating conjunction, introducing a noun/nominal clause
- I believe that everyone has something great to offer the world.
- That she’s a good woman has never been in doubt.
3. Determiner/ Adjective, qualifying a noun within a noun phrase
- That auto-mechanic nearly destroyed my car’s engine.
- She says she cannot tolerate that behaviour.
4. Pronoun, functioning as subject or object in a sentence
- That was all I said. (subject)
- That means a lot. (subject)
- How am I supposed to know that? (object)
- Johnson brought that. (object)
5. Adverbial/Intensifier, modifying an adjective
- Was it that serious?
- How can you be that stupid?