"Either" and "neither" are used in almost the same way as "so" and "too," but they are used with negative verbs.

Examples:

I didn't get enough to eat, and you didn't either.

or

I didn't get enough to eat, and neither did you.

Pay attention to word order. "Either" goes at the end of the sentence after the negative helping verb, and "neither" goes after the conjunction, then the helping verb, and then the subject.

It's important to notice that words following "neither" are not negative. You shouldn't use double negatives in English.

When two situations are the same, you could write a sentence like this:

William doesn't work there, and John doesn't work there.

But this is better:

William doesn't work there, and John doesn't either.

or

William doesn't work there, and neither does John.

Mary doesn't want to wake Tom up, and Christine doesn't either.

or

Mary doesn't want to wake Tom up, and neither does Christine.

He's not very good at painting walls, and she isn't either.

or

He's not very good at painting walls, and neither is she.

She can't wait until the baby is born, and he can't either. *

or

She can't wait unitl the baby is born, and neither can he.

*Modal verbs do the same thing that regular helping verbs do--just repeat from the first part of the sentence.