Ability, Admission and Advice
Basic Modals
Modals verbs modify principal verbs to express various degrees of modality such as necessity, permission, etc. . The most common modals are:
Can
Should
Can I click on this icon?
You should ask for a reciprocal link.
Modal verbs remain in base form for all subjects.
Positive Form:
Subject + Modal + Verb + objects
Can I click on this icon?
You should ask for a reciprocal link.
Negative Form:
Subject + Modal + Not + Verb + objects
Spreadsheet programs can't have been one of the tools Chesterton used to organize his books.
You shouldn't program too many redundancies into the code.
Question Form:
Modal + Subject + Verb + objects
Can you reboot the system quickly?
Should we hack into the company's computer?
Can for Ability and Permission
'Can' is used to speak about abilities as well as asking for or giving permission.
Giving Advice with Should
Use 'Should' to ask for or give advice or suggestions.
Ought to, Had Better
'Ought to' and 'had better' express the same idea as 'should'. Although not as common as 'should' both these forms can be used in place of 'should'.
Example:
We ought to reformat your hard disk.
We ought to edit our current registry.
NOTE: 'had better' is a more urgent form.