This is a fragment from an audio course (I am copying the text literally from printed pages coming with the recordings):
Assistant : I’ve got black in size 38, but not in 39. I’ve brought brown in size 39 for you to try.
Customer: Thanks. I’ll try the 38 first.
Assistant: Oh, they look really nice on you. How do they feel?
Customer: I really like them but they feel a bit tight actually. I think I’ll try the 39[color=blue]s, though I don’t like brown.
Why they feel / it feels , just a tradition? Feeling is entirely customer’s ability and ‘I feel (them / it) …’ would be more logical…
As I can see (hear), informally the 38 is probably used instead of ‘the 38 size’ or instead of the 38’s size trousers, the trousers [of? in?] 38 size.
But in the second case it’s plural - the 39s :shock: !
Is there a typo error? Should be 39’s? Both are OK? What is an (informal?) rule for that?