1. You’d better do (‘d =had) something quickly.
It's an urgent advice.
Better always takes the past form, even though it is used to talk about the present or future. Had is usually contracted to ‘d. In informal spoken English the ‘d’ often dropped (I better go.)
2. You’d better not add anything to my schedule.
Recommendations and advice are taught. (similar)
Had better: give strong advice, or to say what the speaker or others should do. It is generally used to talk about a specific situation, rather than about things in general. It also suggests that something should be done to avoid a bad consequence.
3. I ought to do some volunteer work.
4. You ought to let them do the talking.
It's similar to "should"
Ought to: has a similar meaning to should, but many of its uses have a sense of moral obligation (e.g., I ought to do some volunteer work.). Like Should, it can also have the meaning of “It’s a good idea to …” (e.g., You ought to let them do the talking.), as well as “This is probable or expected” (e.g., That ought to work.)
5. You might want to take a colleague with you.
Want to/might want to: The verb want is often used in giving advice (e.g., You want to be careful.), and is commonly used with might to make a suggestion (e.g. You might want to take a colleague with you= It’s a good idea for you to take a colleague with you.)
1. I’m going to have to do something about it.
2. I’ve got to decide by next week.
3. You don’t have to spend time on this.
Two variations: Going to + have to
“Going to” can soften the strong sense of obligation that have to has, especially when the subject is you (e.g., You’re going to have to do something about this problem,).
Would rather = "prefer to"
Would is usually contracted to‘d in statements.
I’d rather (not) stay in my current job.(‘d=would)
v Over 80 percent of the uses of had better are in affirmative statements. Questions with it are not very common.
v Negative statements with ought to (e.g., That ought not to be allowed.) are not very common in ordinary conversation, where they account for less than 1% of the uses of ought to. They are more common in formal language.
v Over 80 percent of the uses of ‘d rather have the subject I. Over 90 percent are in affirmative statements.
Exercises on " What's advisable, necessary/ and preferabele"