you could say that. i guess. but if you want to sound more native I (personally) would say something like: I got sick a lot this month because of the bad weather. or to shorten it a bit you could say "I got sick a lot this month" saying "fell ill" is almost never said unless you want to act old and stuffy, hahah. You would hear that in a novel, book, or play that was set decades ago. you can say "ill" if you want, but again, its uncommon.

yes, saying have a good day generally applies for the whole day, regardless if it's morning or afternoon. you can also say have a good afternoon, if you want. You sometimes even hear have a good day at night, though that's generally just because people are more used to saying have a good day instead of have a good night.

to do an impression of someone is to act like someone else. take for example, Robin Williams. He does impressions of other people. For example, lets make up a friend. We'll call him Fred. He is into math, chess, and quadratic equations. lets say you on the other hand, are into sports, country music, and can never understand a word he says. If you were to do an impression of him you would change your voice to sound like him and say something like "Look at me, I'm Fred. 2+2 is 4 and you can't move your knight to E5 because that is physically impossible"

Hahah I watched that Big Bang episode last night! Sheldon basically goes crazy, doing all these weird things with fish, and a loom, correct? Sheldon was "off his rocker" which means that someone has gone insane, crazy or are acting unusual. praying he "gets back on his rocker" means they wish Sheldon would stop acting so abnormal and return to his old self. other examples of the expression "off their rocker" would be something like: Grandma's off her rocker...She bought a helicopter! -"What is he wearing?!" -"I don't know, but he must be off his rocker"

No. I think prostitution can put a woman in danger and spread STD's. there is ALWAYS another option besides prostitution.

On is correct. you would use for in that sentence if you're telling the listener what you're having for dinner. like "We are having pizza for dinner on monday"

Honestly, there's no polite way to say fat. there are a number of ways to say it without being so crude. chubby, overweight, big, heavy, well built, big boned.. Personally if you said any of that to me, I'd get a little offended. It's never polite to discuss someone's weight since many people are self conscious about their weight and already know they are too fat, or too skinny. I have a friend who says she's big boned. and another doesnt mind being called chubby. it all depends really. if you have to, I'd say chubby. or just tell them they look cute and fluffy.

some of pie is not correct. Never say that. Some the (or her) pie is correct Some pie is also correct. Some pie or some of her pie can be used interchangeably. some pie just indicates you're having pie. Some of her pie is a little more descriptive.