French language Q&A Forum

I am trying to figure out how to say "I am good/bad at (something)" in French. There seems to be discrepancies between sources online about what prepositions to use.

For example, I searched "I am good at piano" on an online translator. It gave me many options: Je suis doué pour piano, je suis bon au piano, je suis bon en piano, and je suis doué en piano. I know that you use different prepositions depending on what adjective is used (doué vs bon), but why does this translator give so many options, and which ones are correct?

Also, for example, to say "I am bad at guitar", the translator says you can say either je suis mauvais à la guitarre OR je suis mauvais en guitarre. Which one of these is correct?

Basically, which of these prepositions (en/au/à la/pour) do you use when saying je suis nul/mauvais/bon/doué AT something?

Thank you!

Why is de soeurs correct instead of des soeurs?

Your translation corrects "la salle de bain" to "bains" yet other translator translations seem to use either ???????

I understand that "raide" is more common but is "lisse" incorrect? In what context would you use "lisse"?

In the line: "je vais y aller maintenant" why is the "y" included? I thought near future was just aller + infinitive. This also does not seem to be following the rules for "y"as an adverbial pronoun. Thanks!

Im preparing for the B2 DELF in 3 months time and im feeling very behind! but i will push my way through! has anyone got the vocab for b2 or a syllabus? thanks 

I am renovating a house in France. I need to communicate with the workers building construction terms. I would like some exercises with that content please.

I am struggling to work out what the "en" refers to. I presume it is "of something", but can't work out what (or where the "of" comes from) - the sentence seems to work equally well without it.