Which word is to use?

1. The difference between
also/as well/too
Also comes usually before the main verb or after be and it is more formal than as well and too.
e.g.: I went to Munich last year, and I also spent some weeks in Berlin. In British English it is not usually used at the end of the sentence.
Too is much more common in spoken and informal English. It is used at the end of the sentence, but cannot be used in negative sentences!!
"I´m doing my homework now". "I´ll do them, too."
As well is used like too, at least in British English, but in American English as well sounds formal or old-fashioned.

Please remember:
In negative sentences you cannot use too or as well but only "not either"
e.g.: She hasn´t written him either.

Weitere Beispiele:
Jill helped her father in the garden. Joe helped him, too.
               ... oder                       Joe helped him as well.
               ... oder                       Joe also helped him.

Mary went home and so did Eva.
Tom didn´t water the flowers.
Andy didn´t water the flowers either. (kein too!!!!)

2. neither

not one nor the other of two things possible:
Neither of them has/have a house.
Neither is used to show that a statement is also true of somebody/something else: He didn´t remember her birthday and neither did I.
Neither ...nor
It is used to show that a negative statement is true of two things: Neither the computer nor the notebook actually work(s).
Sue didn´t watch TV. Nor/neither did Jim.

3. Kurzsätze I like him - So do I
She doesn´t like him. Nor/Neither do I.
Jill must go home now and so must Jenny.
Dave cannot swim, nor/neither can I.
Marion cannot swim either.

Kurze Sätze im Deutschen in der Bedeutung "auch nicht" werden mit so/nor, neither, not...either gebildet. Dabei wird ein im vorangehenden Satz vorkommendes Hilfsverb oder eine Form von ´to be ´ im Kurzsatz wieder aufgegriffen. Andere Verben werden durch "do" ersetzt.