English grammar
Must / mustn't for strong advice
Give someone strong advice about their health.
From the scene You must rest
In short
Use must + plain verb for strong advice and mustn't when something is not allowed. Should is softer.
Your turn
Which one goes with must + plain verb?
Options: you mustn't eat · you must drink · you must rest (not "must to")
Show answer
must + plain verb → you must drink
How it works
Must + base verb gives firm, strong advice: you must rest. Mustn't says something is a bad idea / not allowed: you mustn't eat anything.
Your turn
Pick the word that fits the line.
Doña Elena is right. You (blank) rest.
Options: must · musts · must to
Show answer
Doña Elena is right. You must rest.
Doña Elena tiene razón. Debes descansar.
Good to know
For softer everyday advice, English often uses should. Must never takes to and never changes: you must rest, he must rest, NOT "you must to rest".
strong advice: must you must rest (not "must to")
Nuria
You must rest, Javi.
Debes descansar, Javi.
Your turn
What fills the gap?
(blank), Javi.
Options: You must rest · You must drink · You mustn't eat
Show answer
Nuria
You must rest, Javi.
Debes descansar, Javi.
must + plain verb you must drink
Elena
Well, you must drink a lot of water.
Pues debes beber mucha agua.
Your turn
What fills the gap?
Well, (blank) a lot of water.
Options: you must drink · you must rest · you mustn't eat
Show answer
Elena
Well, you must drink a lot of water.
Pues debes beber mucha agua.
don't do it: mustn't you mustn't eat
Elena
No, no. You mustn't eat anything today.
No, no. No debes comer nada hoy.
Your turn
What fills the gap?
No, no. (blank) anything today.
Options: You must rest · You must drink · You mustn't eat
Show answer
Elena
No, no. You mustn't eat anything today.
No, no. No debes comer nada hoy.
softer advice: should you should rest
Your turn
What goes with you should rest?
Options: must + plain verb · softer advice: should · strong advice: must
Show answer
you should rest → softer advice: should
Common mistake
Not must to or musts here. A modal: never adds -s, and no to after it.
You must rest, Javi.
Debes descansar, Javi.
Practise it in the story
Meet this rule inside a short animated scene. Answer as it plays, then say the lines yourself.
Practise free in the appSee all forms
| strong advice: must | you must rest (not "must to") |
|---|---|
| must + plain verb | you must drink |
| don't do it: mustn't | you mustn't eat |
| softer advice: should | you should rest |
More lines from the story
- NuriaDoña Elena is right. You must rest.Doña Elena tiene razón. Debes descansar.
- JaviOK... but later I want tapas.Vale... pero luego quiero tapas.
- JaviI'm not thirsty... I'm hungry.No tengo sed... tengo hambre.