Either of the restaurat is/are fine to me.

[wotcha]

1. Neither of the restaurants is my expensive.

2. Neither of the restaurants are expensive.


3. Either of the restaurants is fine.

4. Either of the restaurants are fine.


5. I was invited to two parties last week but I didn't go to either of them.



1 and 2 are both grammatical and I wonder if sentence 4 is grammatical too.

Also I want to know why 'both' can't be used in the sentence 5 instead of 'either'.

 

[emsr2d2]

1. Neither of the restaurants is [STRIKE]my[/STRIKE] expensive.

2. Neither of the restaurants are expensive.


3. Either of the restaurants is fine.

4. Either of the restaurants are fine.


5. I was invited to two parties last week but I didn't go to either of them.



1 and 2 are both grammatical and I wonder if sentence 4 is grammatical too.

Also I want to know why 'both' can't be used in the sentence 5 instead of 'either'.

You will hear 1, 2, 3 and 4. As far as 5 goes, you could use "both" but only if you went to one of the parties. If you went to neither, then you didn't go to either.

To use "both", I would expect to hear something like "I was invited to two parties last week but I didn't go to both of them - I only went to the one that was a five-minute walk from my house". You are simply making it clear that you chose to go to one, but not both.