1_is this sentence correct grammatically? 我是国内人 每个冬天都下雪 2_Could you please make some simple sentence by 下雪天and 下雨天？ 下雪天可以打雪仗，下雨天可以看电影

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.

The first sentence:“我是国内人。”should be“我是本国人。”of couse as for grammer, It's correct,but listener will be confused.

What do you mean by 国内人？Living in the North? 我是北方人 is much better. It always snows in winter. 每个冬天都下雪。 I don't drive in the snow(on snowy days). 下雪天我不开车。