French language Q&A Forum

Bonjour Madame Cécile,

I am facing a difficulty in forming the negative of the following sentence-

"J'aime jouer du piano et de la guitare"

Now, the negative would be as-

"Je n'aime jouer ni du piano ni de la guitare."

Here, will the articles du and de la remain or will they get removed? Because in the lesson it is stated that All articles except the definite articles will be omitted.

But I think jouer du piano and jouer de la guitare are fixed expressions in French so there should be no change in their structure.

Please confirm Madame.

Merci d'avance 

The lesson states " either de or pour is colloquial with abstract nouns (votre compréhension, patience, gentillesse...), with merci de being a bit more elegant.

I don't get the sense of this statement.

If both are colloquial then what is the formal way of expressing " Thank you for your understanding".