Are these sentence sentence correct grammatically?

2. 我在给我去北京的朋友送行。

3. 他和告别妈妈告别的时候，我在看电视机。

4. 除了星期一以外，我还有在星期三和星期四也上课。

5. 我的活儿提高了以后，就我的工资也增加了。

6. 对，外边是正下雪的，别别忘了带上手来你的伞。

7. 我家的附近种着了红颜色的花儿。

8. 在桌子上是正一些书放了书的。

9. 饭馆儿门前停着二十六辆车。

10. 在沙发上躺着的狗是老板的。

11. 我们教室需要三十把椅子。

12. 我在上海待了五天。

13. 你城市的最低气温一般是零下十多少度。

14. 我在商店每天卖三十五斤多苹果。

15. 我做作业两个小时。

16. 在那个事故中一个人死了。

17. 哪个词语的意思跟“确实”这个词的意思是一样的？

18. “真的”这个词的意思和“确实”这个词的意思是一样的吗？

19. “真的”这个词的意思和“确实”这个词的意思有差别吗？

20. “真的”这个词的意思和“确实”这个词的意思相同吗？

21. 上海的空气很潮湿

4. 除了星期一以外，我还有在星期三和星期四上课。

以外 means apart from, except, so you should delete 以外. 还有 means also have, but it should be verb, right? But you want to use an adverb before “在星期三和星期四上课”, right? So you should delete 有. The whole sentence should be 除了星期一，我还在星期三和星期四上课。

5. 我的活儿提高了以后，就我的工资也增加了。

You want to mean that: The amount of my work increases, meanwhile my salary also increases. Right? If so, In Chinese we say 我的活儿多 not 我的活儿提高. So the whole sentence should be 我的活儿多了以后，我的工资也增加了。Or you can also say 我的活儿多了以后，我的工资也就增加了。In this case 就 help you to emphasize the verb 增加. If you want to use 提高, maybe it means the quality of your work is improved. So in this case you can say 我的工作质量提高了以后，我的工资也（就）增加了。

6. 对，外边是正下雪的，毋忘了手来你的伞。

In English you would say: It is snowing. Right you use be verb to express present progressive tense, but in Chinese we don’t use “是”. Also 是…的 means something has some character, e.g. 那个苹果是红色的. But your sentence doesn’t mean the place outside door has some character. It is just present progressive tense. So you may just say: 外边正在下雪。毋 in Chinese means not, but it is in written Chinese, maybe in very formal occasion. So in this sentence 别 is enough. And you want to express that don’t forget take your umbrella with you. You may say 别忘了带你的伞. Also maybe you want to say 带来, in 带来, 来 is a directional complement, but you did not emphasize the direction, right? So you need not use 来. So the whole sentence should be 对，外边正在下雪，别忘了带你的伞。