There are certain everyday French phrases that they never teach you in French class at school because, well, they are English – and they do not always make sense to the native Anglophone.
One of the most perplexing oddities is how the French adopt a plural anglicised form of certain items – such as foodstuffs – instead of the usual singular of the English original. For example, at apéro time, somebody might ask if you would like ‘un chips’ (chips are crisps, not chips – these are frites, of course) instead of un chip (a crisp).
To make matters worse, the French are not really sure if it should be feminine or masculine (une chips or un chips). Dictionaries as far back as Larousse in 1959 and the Robert in 1972 had chips down as masculine while many more today see the word as feminine.
In a similar snack food vein, if you head to a boulangerie to buy a doughnut, they will normally be billed as un beignet (like our traditional filled ones, with apple, jam or chocolate inside). But if you wish to purchase a ring doughnut or one with some form of sugared coating, it may well be billed un doughnuts – yes, that literally translates as 'a doughnuts'.
Finally, one plurality lesson where the French have, in a roundabout way, got it right while still being wrong: France's growing trend for a post-work drink or two with colleagues takes place in what they call the 'Happy Hours' (as seen on a sign outside a bar).
English speakers would use the singular 'hour' even if the reduced-rate duration is, say, two hours – 6pm-8pm. So while 'Happy Hours' sounds wrong, it's spot-on.