Nouns are not always singular in both French and English. Here is a list of words that are singular, uncountable, or invariable in French but are plural or countable in English.
l'actualité news
avoine (fem) oats
une balance scales
la batterie drums
un boxer-short boxer shorts
un caleçon de bain swimming trunks
collant(s)* tights
une cotte overalls, dungarees
un dentier dentures
epsomite (fem) Epsom salts
un escalier stairs
un feu d'artifice fireworks
un fruit (piece of) fruit
un gratte-ciel** skyscraper
la gencive gums
un jean jeans
un jogging sweat pants
laver la vaisselle to do the dishes
une nouvelle (piece of) news
un pain (loaf of) bread
un pantalon pants, trousers
pince(s)* pliers
une pince coupante wire cutters
une pince à dénuder wire strippers
une pince à épiler tweezers
une pince à glace ice tongs
une pince à ongles nail clippers
un porte-monnaie** coin purse, wallet
un pyjama pyjamas
un short shorts
un slip underpants
un slip de bain swimming trunks
un soufflet bellows
la vaisselle (faire la vaisselle) dishes, crockery (to do the dishes)
*These are usually but not always singular in French
**Many French compound nouns are invariable, though their English equivalents are variable
If you can think of any other singular/uncountable/invariable French nouns that are plural or countable in English, please let me know and I'll add them here.
French singulars, English plurals | English singulars, French plurals

