Expressing Obligation

Expressing obligation is an expression telling an action should be done by someone. It can be in the future, at present, or in the past. The language features "should + (present)" is used to tell actions should be done at present, for example: We should study hard. Moreover, to tell an obligation in the future, the sentence uses "should + (continuous)", for instance: You should not be driving too fast. Last, "should + (perfect)" is used to tell an action should have been done in the past, for example: He should have written the letter.

Let's discuss the following dialog.

James    : Dave, I am not sure I can join our meeting this afternoon.

Dave     : What is wrong?

James    : I am not feeling well today.

Dave     : You should go to the doctor.

James   : You are right. Do you know why I am getting sick now?

Dave    : It could be trouble in your life style.

James  : Yes, I should have eaten my breakfast, but I should not. I should have had my lunch, but I am too busy. 

Dave   : That is bad. You should care your health. Don't be too busy. Eating regularly is very important.

James  : Well, I think I should be consulting my health problem to the doctor this afternoon.