Sentences

I have been learning about sentences. When I write a story, I use simple sentences, compound sentences and complex sentences.
- A simple sentence tells 1 thing eg I am a girl. It starts with a capital letter and ends with a fullstop.
- A compound sentence tells 2 things. I am a girl and I am 9 years old. The 2 ideas are joined together to make a compound sentence by putting a joining word in the middle of the 2 ideas - and, but, then, so or because. A compound sentence also starts with a capital letter and ends with a fullstop.