Is either of these.../are either of these...

[CrimsonElevenDelightPetrichor]

Is 'either' singular or plural?
I've been using 'is either of these ' but I'm not sure it's correct.

Help me, oh wise pedants!

Is either of these is correct.

Either is used when referring to one of two things so it's referring to a single item.

It's singular I think.
Replace with one of and you know it's singular.
You would say "is one of these to your liking?"

It's a choice of two so it's one or the other, therefore it is either this one or that one.
So it is either of these.

Using it in a full sentence...

'It is either one of these.'

Thanks that's a good way of remembering.
I've been writing the same sentence repeatedly, and you know how words can look strange after a while.....