"The babies are not sleeping."
Translation:De baby's slapen niet.
's is the plural form for words ending with a, e, i, o, u, y given that the sound is long and the letter in front is a consonant. like: opa’s, azalea’s, ave’s, ski’s, auto’s, accu’s, baby’s.
If the sound is short: lentes (the e sounds not like an /ee/.)
Or if a vowel is in front: abonnees (Before the last e there is another e) essays, bureaus (Same as previous)
One exception is when the accent is used procedés, communiqués