Many ESL writers make a common mistake when using and and not together in a sentence.

The following sentence is correct:

I don’t like apples, and I don’t like bananas.

However, if you combine the subject and verbs to make one sentence it should read:

I don’t like apples or bananas. NOT I don’t like apples and bananas.

Here’s another example:

I don’t eat meat, and I don’t drink alcohol.

If you combine the sentences (this time only the subject is shared), you should get:

I don’t eat meat or drink alcohol. NOT I don’t eat meat and drink alcohol.

This is actually not so much a grammar mistake as it is a logic mistake. There is a difference between “I don’t like peanut butter AND jelly” and “I don’t like peanut butter OR jelly.” The first sentence means you don’t like peanut butter TOGETHER WITH jelly (though you may like peanut butter or jelly separately). The second sentence means you like NEITHER peanut butter NOR jelly.

Finally, if there is no NOT in the sentences you are combining, do not change AND to OR:

I eat meat, and I drink alcohol = I eat meat and drink alcohol

To read more about the logic of AND, OR, and NOT click here.