A2 · Can, want, must
The three ways of saying « must »
« Have to », « must » and « need » — the same three, cut along a different line.
At a glance
- Remember
- ter de and precisar de — only dever stands alone.
- Form
- (eu) tenho deI have to
- Signal words
- ter de
- ter que
- dever
- precisar de
- Trap
- Wrong:Tenho ir às oito.Right:Tenho de ir às oito.
Your turn
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The form
How the forms are built
Each row gives the meaning first, then the form in Portuguese. The colours show what changes from one form to the next.
stem (regular) stem (irregular) person ending negation
| I have to | (eu) tenho de |
| you have to | (tu) tens de |
| he / she has to, you have to | (ele / ela / você) tem de |
| we have to | (nós) temos de |
| you have to, plural and formal | (vós) tendes de |
| they have to, you have to (plural) | (eles / elas / vocês) têm de |
| I ought to | (eu) devo |
| you ought to | (tu) deves |
| he / she ought to, you ought to | (ele / ela / você) deve |
| we ought to | (nós) devemos |
| you ought to, plural and formal | (vós) deveis |
| they ought to, you ought to (plural) | (eles / elas / vocês) devem |
| I need | (eu) preciso de |
| you need | (tu) precisas de |
| he / she needs, you need | (ele / ela / você) precisa de |
| we need | (nós) precisamos de |
| you need, plural and formal | (vós) precisais de |
| they need, you need (plural) | (eles / elas / vocês) precisam de |
| I have to go | tenho de ir |
| you have to wait | tens de esperar |
| I ought to go | devo ir |
| he must be at home | deve estar em casa |
| I need help | preciso de ajuda |
| there is no need | não é preciso |
The rules one by one
The form this topic is about
ter de is necessity from outside.
Tenho de sair às oito.I have to leave at eight.
dever is duty or advice.
Devias descansar mais.You ought to rest more.
dever can also be a guess.
Deve estar a chover lá fora.It must be raining outside.
precisar takes de.
Preciso de falar contigo.I need to talk to you.
Example sentences
Tenho de estar lá às nove.I have to be there at nine.
Não precisas de vir, eu trato disso.You do not have to come, I will see to it.
Devem ter chegado ontem.They must have arrived yesterday.
Devias ter dito antes.You should have said so earlier.
The trap English speakers fall into
Watch out
The de is not decoration. Tenho ir and preciso ajuda are both wrong, and English gives you no warning: « I have to go » and « I need help » have nothing in that position. Dever is the only one of the three that stands without a preposition.
The full explanation
Read it all · about 1 min
Ter de is the hardest: a necessity that comes from outside. Tenho de ir — I have to go, there is no way round it. Colloquially also ter que.
English has three words here too, so the temptation is to pair them off one by one, and the line falls in a different place. Your « must » leans on the speaker's own authority and « have to » on circumstance; here ter de takes both of those, and it is by far the commonest of the three. Dever is not « must » — it is nearer « should ».
Dever is duty or advice: devo ir — I ought to go. It has a second meaning as well, the guess: deve estar em casa is « he must be at home », not « he is required to be at home ».
Precisar de is need: preciso de ajuda, preciso de ir. Before a noun the de is always there, before an infinitive usually.
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The verbs on this page, in every form: ter · dever · estar · chegar · sair · falar · precisar · tratar