Hong Kong People's Common Mistakes in Written English

I was going through my friend's essay today, and found some typical mistakes that a Hong Kong person would make.
1. Although there are many rich people living in Canada, but poor people still exists.
- Although already indicates but. There is no need for a but after the comma.
- People is plural, therefore, no s is needed
Although there are many rich people living in Canada, poor people still exist.

2. Not only was I late, I also missed my class.
- "Not only" is always followed by "but also"
Not only was I late, but I also missed my class

3. You remember me to bring an extra shirt
- remember me (.....I am not dead yet, no need to remember me) (記得我)
- remind me (提醒我)
You remind me to bring an extra shirt

4. There are too many water
- Water is not a countable object..."many" is used for countable object only. Should use "must"
-  Same thing applies to are..."are" is used for countable object too. Should use "is"

5. How to go to the office.
How do I go to the office

As I've said in my previous post. Reading more English books will help improve your English!!!