this question is turning me mad

Yousef, I am sorry to hear that you spent so much time searching for an answer!  You would probably have had better luck if you were searching for incorrect phrases.  But most of these are correct and usable.  The difference is in the meaning. 

so many/too many/very many

"So many" and "very many" have the same meaning - that there is a large quantity of something.  "Too many" indicates there are more than wanted or needed. 

so much/too much/very much

The answer is mostly the same as above.  However, the usage of "very much" is a little different.  One might say "thank you very much," but "very much shopping" is not isn't used.  Stick with "so much" instead.

There are many way that you can say thank you.  Using "thanks" is more informal.  Adding "so much" or "so very much" indicate a greater degree of appreciation.  It often is used to recognise that the person did something more than was expected or gave in some way that deeply affected you.  I would take "thanks too much" off your list.  You can also use "many thanks" as well. 

Hi Yousef, 

It's generally better to ask new questions in a new thread, since people are more likely to look at it and answer it, however - here goes!

1. You are correct - neither/either point to two options.
However, example 2, "either of you has broken my coffee cups" is not correct. You would be better to say "one of you has broken my coffee cups". 

We don't usually use "either" when referring directly to people, though awkwardly, you can use the phrase "if either of you..."

You can also say "neither of you has broken my coffee cups". 

2. Neither/Nor are both acceptable. Nor is slightly more old-fashioned, but is not informal. The thing to remember is to make sure your either/or and neither/nor agree. (So don't use either/nor or neither/or.)

3. Either version of this sentence is correct - it's entirely up to you which you use. If the sentence is part of a longer piece, you may wish to make sure that the styles between sentences agree. 

"Jane doesn't like dogs, neither does Kate. I don't like cats, neither does John."

"Jane doesn't like dogs, nor does Kate. I don't like cats, nor does John." 

Hope that all helps!

hi

can you help with this three small questions:

1- in these examples:

-Neither of them is interested in your project

-Either of you has broken my coffee cups

-Either of these rooms will serve me as a study

-Neither of my sisters is abroad

here neither/either are pointing to just and only just ((TWO)) people or things right?

2- in these examples:

-he didn't remember, neither/nor did I

-I won’t accept bribes.
   —Neither/Nor will I.

which is formal and which is informal (neither or nor)?

3- "i don't like cats neither/nor does john" is this sentence correct?

please help me by answering each question by itself and many thanks for your patience and help in advance =)