I think you can get away with all of them. I’d say they are all okay.

too means also, http://www.thesaurus.com/browse/too?s=t

All of them sound correct to me. However, since you asked about the difference, I will try to answer it: *You use 'also', 'too', or 'as well' when you are giving more information about something. 1) ''Also'' is usually used in front of a verb. If there is no auxiliary verb, you put 'also' immediately in front of the verb, unless the verb is 'be'. E.g.: ''They also helped out.'' (with 'be'): ''We were also very happy!'' *Also is sometimes put at the beginning of a clause. = ''She is very intelligent. Also, she is gorgeous.'' (don't put 'also' at the end of a clause!) 2) ''too'' is usually used at the end of a clause. = ''I will miss you, too.'' *'Too' is sometimes put after the first noun phrase in a clause. = ''I wondered whether I too would become ill''. 3) ''As well' always goes at the end of a clause. E.g.: ''They will have a difficult year next year as well.'' 4) In 'negative clauses', you don't usually use 'also', 'too', or 'as well'. Use ''either'': E.g.: ''I'm not going to that party, either.'' Hope that helps!

they are not all ok an is one we is plural meaning more than one, so are two people going to share one ice cream? the - is not needed so just ice cream I want an Ice cream too we want ice cream too< meaning we each want our own ice cream serving both of these are fine : "Haven't they gone to England as well ?" - "Haven't they also gone to England ?" - "Haven't they gone to England either ? drop the ether Haven't they gone to England? Haven't they gone to England also?

look up thesaurus and Synonyms when you are not clear on how a word works or its meaning. either Synonyms are: one of two Synonyms are other meanings of the word, a thesaurus will give a list of words with like meanings http://www.thesaurus.com/