Giving advice/ making suggestions

formal	semi-formal	infornal
I strongly advise you  to seek help. / You need outside help,  I’m afraid.	My advice is that  you need help./ I think you’ll have to get outside   help.	You need help, I tell you / You can ‘t do it on your  own.
If I may suggest, you’d  need to look into this  more carefully.	I suggest that you (should) look   into this more carefully.	Look into this more   carefully.
It’d be in your interest   not to delay any   further. / You oughtn’t to delay  any further.	You shouldn’t delay any    further. / (If I were you,) I shouldn’t delay  any further.	Don’t delay anymore.
It’d be advisable for   you to leave now.	I’d advise you to leave now.	You’d ( had better/ had best)   leave now.
It’d be a good change  to eat out tonight.	Shall we eat out tonight? / I suggest we eat out tonight.	What do you say to eating   out tonight? / Suppose we eat out tonight. / How about.../ What about.../ Why don’t we .../ Let’s ...
You could try his  home number (landline).	You can try his home number,   if you like.	Try his home number.