Common mistakes

1. Let me know if you have any comments and suggestions.
- plural is recommended, because it is stressing for more than one. Use of "comment" is not incorrect.
2. The only time you should spell “let’s” with an apostrophe is when it means “let us”: “Let’s go to the mall.” If the word you want means “allows” or “permits,” no apostrophe should be used: “My mom lets me use her car if I fill the tank.” Reference