(For reference, I'm 17 and am responding as such)
Cleaning, studying, sporting activites.
While there are people who do these things, they prove to be on the whole uncommon activities. If these things are being done it is likely they don't consider the time they do these things with 'free time'.
We prefer to relax, be unbothered, and see what's going on on Y0uTube or social media, or just watch TV.
I haven't seen anything but cowardice and expediency.
Two things to keep in mind when you're deciding whether to use formal or informal English are the B) occasion and the audience.
Of course you are going to change the way you talk depending on whether you are speaking to your friends or to your teacher - usually with the teacher you are going to use more formal English.
Occasion is also important - you won't speak in the same manner at a party and a cocktail.
Answer:
Stay true to what you believe
