1. the grammar is correct~ However, if you would like to make it better~ 我是國內人 = 我是本國人(/當地人), which means I'm a local person. 每個冬天是下雪天 ； If what you're trying to say is it always snow in the winter' , then you could say 每"次"冬天都會下雪, which literally translation is "every time the winter comes, it always snow." 〔每次means "every time"；都會means "always" 〕 2. 下雪天、下雨天, for example, in English you might say, today is a rainy/snowy day. Generally speaking in Chinese we'll say, 今天下雨or今天下雪, rather than 今天是(個)下雨天. I mean grammarly it's correct, but not really sth we'll use in our daily expression. ( PS. you could put the "yea(耶..)" sound at the end of this sentence, showing surprise or bad feeling, to be more like a native. If you want to show the happiness, then simply just make your tone go up; on the opposite, to show your depression just goes down your tone.) So, basically "yea(耶..)" is just an auxiliary word.