when des becomes de, d'

Question

If des becomes de in front of an adjective that precedes a noun, why is 
this correct:  je suis jaloux des nouvelles bottes ....? Here des is used preceding the adjective...

Maarten Kamp · Answer

Claudia,

The link attached to your post doesn’t seem to be connected to the question.

However, the reason is that this not the partitive ‘ des ‘, but the obligatory contraction of ‘ de les ‘ - that is the preposition ‘ de ‘ followed by the definite article ‘ les ‘. The expression is “ jaloux de qqc “

https://www.wordreference.com/fren/jaloux

This is covered in lesson attached below as :

ATTENTION:

This rule doesn't apply when des is the contraction of "de + les" (= of/from/to the) :

J'ai acheté de nouvelles bottes.I bought [some] new boots.

BUT

Je suis jalouse des nouvelles bottes que tu as achetées.I'm jealous of the new boots you bought.

"Des" becomes " de/d' " in front of adjectives preceding nouns (French Articles)