one of …

After one of we normally use a plural form.

• one of our cats (not one of our cat)

Occasionally one of is used with a singular noun referring to a group.

• Why don’t you ask one of the crew?

A following verb is normally singular.

• One of our cats has disappeared. (not One of our cats have disappeared.)

After one of, a noun phrase must have a determiner (e.g. the, my, those).

• one of the/my/those horses (but not one of horses)

Of cannot be dropped.

• one of my friends (not one my friend) or one my friends

note

For sentences like She’s one of the few women who have/has climbed Everest, (see here).