Doesn't "I'm not dating his friend, too!" sound weird? I think too should be either, but even if it is either, it sounds weird. The translation goes "I'm not in the middle of dating his friend. either"
ex)Dear Advisor,
My boyfriend, Paul, never wants to got out with just me. He always brings his best friend with him when we have a date. He says that he feels bad if he doesn't invite his friend. But sometimes I get angry because I want us to be alone. I'm not dating his friend, too!
Context, as usual, is everything. At the beginning of your post, I agreed with you that it should be "either". However, when I got down to the actual story, I realised that "too" is correct. You don't need the comma.
We never go out alone. He always brings his friend. I'm not dating his friend too!!
This could also be written "I'm not dating his friend as well".
If you wanted to avoid any possible confusion or ambiguity, you could say "I'm not dating his friend, I'm dating him!"
I would omit the comma before "too". It reads wrongly with the comma.
I would say that the original sentence is wrong with a comma.
A negative statement would involve "either" if you were saying that you and another person are not dating his friend.
- My boyfriend is called John.
- Is he nice?
- Yes, he's lovely. He has a friend called David.
- I know. I've met David.
- Are you dating him?
- No! I'm not dating him! Are you?
- NO! I'm not dating him either.
The two people involved are both "not dating his friend" therefore "either" would be appropriate.
In your original sentence you are not saying that you are one of two people who is not dating his friend. You are simply stating that you are not dating his friend in addition to dating him (your boyfriend).
If a statement can be replaced by "Nor am I" which would be possible in the dialogue I gave above, then "either" is correct.
With your original piece it would not be possible to say "Nor am I" instead of "I'm not dating him too".
In my opinion, the sentence, "I'm not dating his friend too" should be commaless because i) 'too' refers only to 'his friend', not the whole sentence, and ii) the intonation or prosody of the sentence indicates that there is no pause here. If there was a pause, the 'too' would refer to the whole sentence. The meaning would be "Also, I'm not dating his friend." or "I'm not dating his friend either" - which is not the meaning.
Last edited by Raymott; 21-Jul-2011 at 11:39.