Why “du” is used instead of “de” [duplicate]

Question

This question already has an answer here:

• Quand « du » et quand « de » ? 2 answers

I read the following sentence:

"avoir le nom du père"

Why wasn't "de" used instead of "du"?

Thanks.

Answer 1

“Du”, in this example, is a contraction of “de le”, meaning “of the”.

So the construct might have been “le nom de le père", except that “de le” doesn't sound very good, so it is incorrect. You need the contraction “le nom du père”.

“De la” sounds (or is believed to sound) better, so the construction for mother would be “de la mère”.