Permission, obligation and necessity

Wearing a tie is optional in this restaurant. You don't ... in this restaurant

Wearing a tie is optional in this restaurant. You don't HAVE TO WEAR A TIE in this restaurant

You .. back before next month

You NEEDN'T PAY ME back before next month

You ... you didn't like the pasta. You know how sensitive he is about his cooking

You SHOULDN'T HAVE SAID you didn't like the pasta. You know how sensitive he is about his cooking

You aren't ... your mobile phone when you are driving

You aren't PERMITED TO ANSWER your mobile phone when you are driving

You can't take flash photographs in this museum. Flash photography is ... in this museum

You can't take flash photographs in this museum. Flash photography is NOT ALLOWED/PROHIBITED in this museum

You ... to go into the art gallery. Entrance is free.

You don't NEED TO PAY to go into the art gallery. Entrance is free.

You don't have to bring your car - we can go in mine. You ... - we can go in mine.

You don't have to bring your car - we can go in mine. You ... DON'T NEED TO BRING YOUR CAR/NEEDN'T BRING YOUR- we can go in mine.

You'd ... late - you know what Jane is like about punctuality

You'd BETTER NOT TO BE late - you know what Jane is like about punctuality

I regret losing my temper last night. I shouldn't ...last night

I regret losing my temper last night. I shouldn't HAVE LOST last night

A lot of people think that governments ... more to protect young people health

A lot of people think that governments OUGHT TO BE more to protect young people health

I must finish the sales report by Friday. I've ... by Friday

I must finish the sales report by Friday. I've GOT TO FINISH IT by Friday

Officialy you musn't park here - but everyone does. You aren't ... here

Officialy you musn't park here - but everyone does. You aren't ALLOWED TO PARK here

Put that cigarette out. This is a no-smoking area. You'd ... . This is a no-smoking area

Put that cigarette out. This is a no-smoking area. You'd BETTER PUT IT OUT . This is a no-smoking area. (NO es correcto BETTER -TO- PUT) - Strong recommendation with consequences if not.

We ... sweaters after all- it's really warm!

We NEEDN'T HAVE BROUGHT/TAKEN sweaters after all- it's really warm! (NO es correcto NEEDN'T -TO- HAVE BROUGHT /TAKEN)

Wearing a seat belt in the back seat of the car is compulsory. You ... in the back seat of the car

Wearing a seat belt in the back seat of the car is compulsory. You HAVE TO WEAR A SEAT BELT in the back seat of the car

Smoking ... anywhere on the aircraft

Smoking IS NOT ALLOWED anywhere on the aircraft

Swimming in the lake is strictly prohibited. You aren´t ... in the lake

Swimming in the lake is strictly prohibited. You aren´t ALLOWED TO SWIM in the lake

The best thing to do would be to get specialist advice. You really ... specialist advice.

The best thing to do would be to get specialist advice. You really HAD BETTER GET specialist advice.