One of the meanings of the modal auxiliary should is advisability:
--You should leave right now.
--They should fill out this form. You can also express the same idea using either ought to or had better:
--You ought to leave right now.
(You had better leave....)
--They ought to fill out this form.
(They had better fill out....)
Should and ought to both mean that something is a good idea. Had better is usually stronger, implying a warning of bad consequences.
The negative of should is shouldn't. Ought to is not usually used in the negative. Often you will hear people pronounce ought to as otta.
--You should leave right now.
--They should fill out this form. You can also express the same idea using either ought to or had better:
--You ought to leave right now.
(You had better leave....)
--They ought to fill out this form.
(They had better fill out....)
Should and ought to both mean that something is a good idea. Had better is usually stronger, implying a warning of bad consequences.
The negative of should is shouldn't. Ought to is not usually used in the negative. Often you will hear people pronounce ought to as otta.
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