Deber Present Tense Conjugation in Spanish

The present tense of deber — to have to — is the form you need for habits, facts and what is happening now. Deber means must and should: deber + infinitive is an obligation (debo estudiar), while deber de + infinitive expresses probability (debe de estar enfermo). It is regular, but learners often confuse it with tener que, which is the stronger, more everyday way to say have to. This page gives you the complete present tense table for deber, how it is formed, when to use it, the mistakes learners make with it, and a quiz to check yourself. The first example shows it in action: “Yo debo estudiar para el examen.” — “I must study for the exam”.

Present tense conjugation of deber

Every form in the table below comes from VerbFlow’s verified conjugation tables for deber. Deber is a regular -er verb, so you can build the present tense from the regular endings once you know the stem.

Present tense indicative — deber

Person Form
yo debo
tú debes
él/ella/Ud. debe
nosotros/as debemos
vosotros/as debéis
ellos/ellas/Uds. deben

The gerund of deber is debiendo and the past participle is debido. You need the participle for the perfect tenses and the gerund for the progressive with estar.

How the present tense of deber is formed

For a regular -er verb, the present tense is built on the stem deb- (the infinitive deber without its -er ending) plus the present tense endings: yo → debo, tú → debes, él/ella/Ud. → debe, nosotros/as → debemos, vosotros/as → debéis, ellos/ellas/Uds. → deben. So deber gives debo, debes, debe, debemos, debéis and deben. There is nothing irregular to memorise for this verb in this tense — the endings do all the work, and the stress falls where the endings put it.

A note on spelling: the written accents in this tense are part of the form, not decoration. In the present tense, debéis carries an accent, and leaving it out changes the pronunciation and, in writing, marks the form as wrong. Copy the forms from the table above exactly, accents included.

When to use the present tense of deber

1. Habits and routines

Use the present for things you do regularly. For example, with deber: “Yo debo estudiar para el examen.” — “I must study for the exam”. Notice how the time expression and the context, not just the verb form, tell you which rule applies.

2. General truths and facts

Use the present for things that are always true. For example, with deber: “Ella debe llegar antes de las ocho.” — “She must arrive before eight”. Notice how the time expression and the context, not just the verb form, tell you which rule applies.

3. What is happening right now

Use the present for actions in progress at this moment. For example, with deber: “Nosotros debemos entregar el trabajo hoy.” — “We must hand in the work today”. Notice how the time expression and the context, not just the verb form, tell you which rule applies.

4. Scheduled plans and the near future

Use the present for fixed plans, especially with a time expression. For example, with deber: “Ellos deben respetar las normas.” — “They must respect the rules”. Notice how the time expression and the context, not just the verb form, tell you which rule applies.

Present vs future: deber now, deber later

The present and the future both talk about things that have not happened yet in one sense, but they are not interchangeable. The present is for what is true now or already fixed; the future is for what will happen and is not yet certain. Compare the pairs below — the present form comes from this page, the future form from the full conjugation table.

  • Present tense tense: “Yo debo estudiar todos los días.” — “I have to study every day.”

  • Future: “Yo deberé estudiar mañana.” — “Tomorrow I will have to study.”

  • Present tense tense: “Ella debe estudiar ahora.” — “She has to study now.”

  • Future: “Ella deberá estudiar la semana que viene.” — “Next week she will have to study.”

  • Present tense tense: “Nosotros debemos estudiar en clase.” — “We have to study in class.”

  • Future: “Nosotros deberemos estudiar el lunes.” — “On Monday we will have to study.”

Example sentences: deber in the present tense

Six sentences using only the present tense of deber, with English translations. Read them aloud — saying the forms is the fastest way to fix them in memory.

  • “Yo debo estudiar para el examen.” — “I must study for the exam.”
  • “Ella debe llegar antes de las ocho.” — “She must arrive before eight.”
  • “Nosotros debemos entregar el trabajo hoy.” — “We must hand in the work today.”
  • “Ellos deben respetar las normas.” — “They must respect the rules.”
  • “¿Tú debes hacer los deberes?” — “Must you do your homework?”
  • “Vosotros debéis escuchar al profesor.” — “You must listen to the teacher.”

Common mistakes with deber in the present tense

Mistake 1

Wrong: Yo debo de estudiar — wrong use of de.

Right: Yo debo estudiar.

Obligation is deber + infinitive; deber de + infinitive means probably.

Mistake 2

Wrong: Yo deber estudiar — using the infinitive.

Right: Yo debo estudiar.

Deber conjugates like any verb: debo, debes, debe — never the bare infinitive.

Quiz: deber in the present tense

Eight questions on the present tense of deber. Answers with explanations follow each question.

1. What is the yo form of deber in the present tense?

  • A) debo
  • B) debes
  • C) debe
  • D) debemos

Answer: A — The yo form in the present tense is debo.

2. What is the tú form of deber in the present tense?

  • A) debo
  • B) debe
  • C) debemos
  • D) debes

Answer: D — The tú form in the present tense is debes.

3. What is the él/ella/Ud. form of deber in the present tense?

  • A) debes
  • B) debemos
  • C) debe
  • D) debo

Answer: C — The él/ella/Ud. form in the present tense is debe.

4. What is the nosotros/as form of deber in the present tense?

  • A) debe
  • B) debemos
  • C) debo
  • D) debes

Answer: B — The nosotros/as form in the present tense is debemos.

5. Fill in the blank: “Yo ___ estudiar para el examen.” (I must study for the exam.)

  • A) debo
  • B) debes
  • C) debe
  • D) debemos

Answer: A — The sentence needs debo.

6. Fill in the blank: “Ella ___ llegar antes de las ocho.” (She must arrive before eight.)

  • A) debo
  • B) debes
  • C) debemos
  • D) debe

Answer: D — The sentence needs debe.

7. Which sentence is correct?

  • A) Yo debo de estudiar — wrong use of de.
  • B) Yo debo estudiar.

Answer: B — Obligation is deber + infinitive; deber de + infinitive means probably.

8. Which sentence is correct?

  • A) Yo debo estudiar.
  • B) Yo deber estudiar — using the infinitive.

Answer: A — Deber conjugates like any verb: debo, debes, debe — never the bare infinitive.

Frequently asked questions

Is deber regular in the present tense?

Yes. deber is a regular -er verb and its present tense follows the standard endings, so once you know the stem deb- you can build all six forms. The only thing to watch is the spelling of the endings themselves, including the accents.

What is the yo form of deber in the present tense?

It is debo. The yo form is the one learners use most and the one that most often breaks the pattern — for deber it is the form to learn first, before the rest of the table.

When do I use the present tense of deber instead of the preterite?

Use the present when the action is a habit, a fact, or happening now, and the preterite when it is a finished action in the past. If you can add “yesterday” to the sentence and it still makes sense, you almost certainly need the preterite, not the present.

How can I remember the present tense forms of deber?

Say the six forms aloud in order — debo, debes, debe, debemos, debéis, deben — three times a day for a week, always in a sentence, never as a bare list. Then use the Spanish Verb Quiz to test yourself, and the full conjugation page for deber to see the verb in every tense.

Say it yourself

Reading is not enough — say the verb aloud before you move on. Use the forms from the tables on this page and answer these three prompts as full sentences. First, say a sentence about yourself in the present tense: “Yo debo…”. Second, say a sentence about yesterday in the preterite: “Ayer yo debí…”. Third, say a sentence about tomorrow in the future: “Mañana yo deberé…”. If you can answer all three without looking at the tables, the forms are starting to stick. If you hesitate, go back to the examples above, read them aloud twice, and try again. Speaking the forms is what turns a table you have seen into a verb you can use.

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