Level: beginner
Suggestions
We use should and shouldn't to make suggestions and give advice:
You should send an email.
You shouldn’t go by train.
We also use could to make positive suggestions:
We could meet at the weekend.
You could eat out tonight.
Level: intermediate
We can use conditionals to give advice:
Dan will help you if you ask him.
Past tenses are more polite:
Dan would help you if you asked him.
- Suggestions 1
- Suggestions 2
Level: beginner
Obligations
We use must or need to to say that it is necessary to do something:
You must stop at a red light.
Everyone needs to bring something to eat.
You can wear what you like, but you must look neat and tidy.
We use mustn't for prohibitions – to say that it is necessary to not do something:
You mustn't make any noise in the library.
You mustn't say anything to her. It's a surprise.
We use had to (positive) and couldn't (negative) if we are talking about the past:
Everyone had to bring something to eat.
You couldn't make any noise in the library.
- Obligations 1
- Obligations 2
Thank you for your clarification, Mr. Pete.
Normally, I would only use "should not" after "suggest" to mean "show" or "express", as in:
> The result suggests that we shouldn't...
Now, I think I'll start using "should not" after "suggest" when I make a recommendation or give someone else advice in some case without worrying too much.