Pairs of things
A pair of anything is a single thing. For instance, a pair of pants is one single item. So it needs a singular verb:
My pair of pants is lying on my bed.
When you put ‘pair of’ in front of something, the word ‘pair’ becomes the subject, and the ‘of...’ part is a phrase that tells you more information about the pair - what it’s a pair of. Say you have a plural subject ‘socks’:
My socks are lying on the bed.
By putting ‘pair of’ in front of the subject ‘socks’, you change the subject to being ‘pair’, which is singular, rather than ‘socks’, which is plural:
My pair of socks is lying on the bed.
This is correct, although sometimes it looks a bit funny because you’ve got the plural word ‘socks’ right next to a singular verb ‘is’. You’ve just got to remember that the ‘is’ verb is connected with the word ‘pair’, not the word ‘socks’.
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