Obligations - "Hay que, tener que, deber"

What are hay que, tener que and deber for?

• All three express obligation or that something is necessary.
• They all go with an infinitive (the basic verb form: cocinar, hacer, comprar…).

But they do not mean exactly the same. The difference is:

• hay que + infinitive → impersonal obligation (in general, people / we / you).
• tener que + infinitive → personal obligation (I, you, he… have to).
• deber + infinitive → moral duty or recommendation (should / ought to, must).

Hay que: general obligation (no subject)

• Form: always hay que + infinitive.
• Never changes. There is no yo hayo que, nosotros hay que, etc.
• Used when the subject is not a specific person.

• Often used in rules, instructions, “how to” explanations.
• Think of English: “you have to / one must / you need to …” in a general sense.

Tener que: concrete obligation (who has to do it?)

Use tener que + infinitive when a specific person has to do something.

• It is similar to English “to have to / need to”.
• Tener is a normal verb; it conjugates for each person.

• Use it for real, concrete obligations, not just advice.
• Typical in everyday speech: appointments, tasks, deadlines.

Deber: duty or recommendation (should)

Deber + infinitive expresses that something is a good idea, a moral duty or a strong recommendation.

• Often close to English “should / ought to”.
• Sometimes feels softer than tener que (less “you must”, more “you should”).

• You will often hear it in polite advice or suggestions.
• In some contexts it can be quite strong (“must”), but at A1 level, think mainly “should”.

Choosing between them: quick decision guide

1. Is it a general rule, no clear subject?
   → Use hay que.
   • Ej.: En este restaurante hay que reservar mesa.
2. Is it a specific person, and it is really necessary?
   → Use tener que.
   • Ej.: Yo tengo que reservar la mesa hoy.
3. Is it more advice / what is a good idea?
   → Use deber.
   • Ej.: Nosotros debemos reservar con tiempo.

Typical mistakes to avoid

• Conjugating “hay que”
  • Yo hayo que cocinar → Yo tengo que cocinar.
  • Nosotros hay que comprar pan → Nosotros tenemos que comprar pan (if you mean “we have to”).
  • Remember: only hay que, never changes.
• Adding “que” after deber
  • Debo que limpiar la mesa → Debo limpiar la mesa.
  • Correct pattern is deber + infinitive, no que.
• Forgetting to conjugate “tener” or “deber”
  • Yo tiene que cocinar → Yo tengo que cocinar.
  • Tú debe estudiar → Tú debes estudiar.

Mini contrast: same idea, different focus

Look at how the focus changes:

Step-by-step: build your own sentences

1. Decide the subject
   • No specific person? → hay que.
   • Specific person? → tener que or deber.
2. Choose the strength
   • Strong, real obligation → tener que.
   • Advice / good idea → deber.
3. Conjugate the verb
   • For hay que → no conjugation, just “hay”.
   • For tener or deber → match the person (yo, tú, él…).
4. Add the infinitive
   • Use a base verb: comprar, cocinar, limpiar, estudiar…

Example sequence:

• Context: you personally have a meeting at 9.
• Subject: yo → specific person.
• Type: strong obligation → tener que.
• Verb: llegar (to arrive) → infinitive.

Result: Tengo que llegar a las nueve.

Self-check: can you do this?

• Can you explain in your own words the difference between hay que, tener que and deber?
• Can you make one sentence with each, about your real day?

For example, try to say:

1. One general rule in your job or home with hay que.
2. One personal obligation today with tener que.
3. One thing you know is a good idea for you with deber.

If you can do this clearly, you have the grammar you need to start using it confidently in conversation.