Разница между must, have to/has to и should заключается в оттенках.
✔️ Must — должен. Это модальный глагол. Он самый сильный из трёх представленных. Он выражает (святую) обязанность, убеждённость, моральный долг, строгое соблюдение правил, законов, распоряжений.
For example:
📌 I must restore justice.
📌 As a man you must provide your family with everything necessary.
📌 You must obey the law, if you don't wanna* end up behind bars.
♠️ В разговорной речи его можно услышать в значении непременно должен, как добрый совет.
For example:
📌 You must stop eating junk food so much. You don't wanna die before 60, do you?
📌 When you visit Moscow, you must see the Red Square.
♠️ Must можно использовать, когда Вы пришли к какому-то заключению. В такой ситуации Вам понадобится следующая формула: MUST+HAVE+V3... Это называется Perfect Infinitife.
For example:
📌 Tom must have had a nightmare. He was tossing and turning in bed all night.
📌 I can't find my charger. I must have left it at home.
♠️ В разговорном английском must можно использовать в качестве существительного.
For example:
📌 I highly recommend that you watch this movie. It is a must, dude.
📌 I work out three times a week to keep myself in shape. It's a must if you want to stay looking good after forty.
✔️ Have to — вынужден, должен (менее категорично). Здесь «должен», потому что внешние обстоятельства вынуждают, заставляют, требуют сделать это именно так.
For example:
📌 Tom has to work the graveyard shift on Sunday.
📌 Jenny has to wake up early tomorrow because she has a lot of work to do.
📌 It's so cold outside, but I have to go to the store because I'm running out of bread and some other stuff. And what's more, I have to walk the dog.
📌 They have to appear in a minute or two.
📌 In Russia, all men aged 18–30 have to serve in the army.
Можно использовать have/has got to вместо have to. Обратите внимание как строятся вопросы с have/has got to и have to.
For example:
📌 Have I got to have a good crew to achieve success in business ?
📌 To achieve success in business, you've got to have a good crew.
📌 Does he have to go out of town until everything is settled down?
📌 Has he got to go out of town until everything is settled down?
Напишите в комментариях в чём смысловая разница между этими двумя предложениями:
1) Everyone in the office has to chip in to buy a gift for the boss. It isn't mandatory, but it will reflect poorly on them if they don't.
2) Everyone in the office must chip in to buy a gift for the boss. He is so generous and has done so much for his employees.
Achtung❗
В отрицании must и have to значительно отличаются по значению. В отрицательных предложениях mustn't выражает строгий запрет=don't do it, а don't have to/doesn't have to /didn't have to говорит о том, что не нужно что-то делать, нет необходимости что-то делать.
For example:
📌 We don't have to cook today. I ordered lots of food from the restaurant.
📌 Jenny loves weekends because she doesn't have to get up early.
📌 Richard doesn't have to wear a suit to work, but he usually does.
📌 I mustn't eat too much.I'm supposed to be on a diet.
📌 You mustn't talk to your mother like that.
📌 Men must not be careless.
✔️ Should — следует. Это модальный глагол, который помогает выразить совет или рекомендацию.
For example:
📌 You should dress warmer. It's so cold outside.
📌 You should watch this video. It's really fun.
📌 Should we trust him?
📌 You shouldn't eat souch sugar if you want to be fit.
♠️ Should можно использовать, когда что-то должно было произойти, но не произошло.
For example:
📌The train should have arrived at 9:30 am, but it was 20 minutes late.
📌She should have known that he is a junkie when she married him.
♠️ Should также можно использовать, когда Вы пришли к заключению, что так и нужно было поступить в той или иной ситуации.