Modal verb: Should

example:

Here the scientist suggests to his colleague:
"I think you should be more explicit here in step two..instead of writing then we need a miracle..."







You should do something = means it is the right thing (or a good thing) to do
Should is used to give advice or to give an opinion.
examples:
- Your English needs a review. You should study some grammar.
- The government should do something concrete to help this country.
- Should we invite Mark for my birthday? Of course, we should! 
- You shouldn't run, is very slippery.  (negative form)

• Should is not as strong as must or have to: - You should apologise to her (it would be a good thing to do) ; You must / have to apologise to her (you have no alternative)

• It is possible to use should when something is not right or what we expect: - I wonder where Matteo is. He should be already here by now; - The price of this book is wrong, it should be 10€ not 100€

• Should can be used to comment on something we expect: - There shouldn't be any problem on finding a Hostel in Barcelona in two weeks.

• Should is often used after some verbs like: DEMAND, INSIST, PROPOSE, RECOMMEND, SUGGEST

ALSO
Should is often used in the first conditional hypothetical constructions:                     if + should + infinitive:

example
- If you should happen to miss the train, I could drive you there myself.

- Should you wish to change your holiday arrangements, we will all we can to help.  (very formal situation, in written English)

we are going to review conditional situations a bit further