Mentir Examples, Sentences & Quiz in Spanish

mentir means "to lie" in English, and this page shows you how it actually sounds in everyday Spanish — not just the conjugation table, but the verb in real sentences, in short dialogues, and in the mistakes learners make with it. Mentir means "to lie", and it is the verb for saying something you know is not true — a small white lie, a big lie, a lie to your parents, a lie on a form. It is an -ir stem-changing verb: the e becomes ie in yo, tú, él and ellos (miento, mientes, miente, mienten) but stays e in nosotros and vosotros (mentimos, mentís). Its gerund is also irregular — mintiendo, not mentiendo — because the stem change carries into the gerund. The contrast with decir la verdad (to tell the truth) is the natural pair for this verb, and learners should know both. Below you will find twelve example sentences grouped by meaning, two short dialogues, the most common mistakes with corrections, and a ten-question quiz with explained answers. If you want the full tables first, start with the full conjugation of mentir; if you want to study one tense in depth, see the mentir present tense page.

mentir in everyday use: examples with translations

Lying to people

  1. Tú mientes a tus padres. — "You lie to your parents."
  2. Mi hermano miente sobre su edad. — "My brother lies about his age."
  3. Ayer tú mentiste a tu madre. — "Yesterday you lied to your mother."
  4. De niño, yo mentía mucho. — "As a child, I used to lie a lot."

Not lying

  1. Yo nunca miento. — "I never lie."
  2. Nosotros no mentimos a nuestros hijos. — "We don't lie to our children."
  3. Yo no mentiré jamás. — "I will never lie."
  4. Yo nunca he mentido a nadie. — "I have never lied to anyone."

Why people lie

  1. Ellos mienten por miedo al castigo. — "They lie out of fear of punishment."
  2. Ella miente para protegerse. — "She lies to protect herself."
  3. Yo mentiría si fuera necesario. — "I would lie if it were necessary."
  4. Vosotros mentís a vuestros profesores. — "You lie to your teachers."

mentir in conversation

Two short dialogues that use mentir the way people really speak it. Notice how the verb changes with the person, and how the same verb fits different situations.

A mother catches her son in a lie.

  • Madre: Tú mientes a tus padres. — "You lie to your parents."
  • Hijo: Yo nunca miento. — "I never lie."
  • Madre: Tú mientes cuando dices eso. — "You lie when you say that."
  • Hijo: Ayer tú mentiste a tu madre. — "Yesterday you lied to your mother."

Two friends talk about honesty.

  • Ana: Nosotros no mentimos a nuestros hijos. — "We don't lie to our children."
  • Luis: El político miente en cada discurso. — "The politician lies in every speech."
  • Ana: Ellos mienten por miedo al castigo. — "They lie out of fear of punishment."
  • Luis: Yo no mentiré jamás. — "I will never lie."

Common mistakes with mentir

The errors learners actually make with mentir, each with the wrong form, the right form, and why the right form is right.

✗ *Yo mento jamás (no stem change).

✓ Correct: Yo no miento jamás.

Mentir is an e → ie stem-changing verb: yo miento, not mento. The change hits yo, tú, él and ellos.

✗ *Nosotros mientimos poco.

✓ Correct: Nosotros mentimos poco, preferimos la verdad.

Nosotros and vosotros keep the plain stem: mentimos, mentís. The ie change never reaches them.

✗ *Yo he miento.

✓ Correct: Yo nunca he mentido a nadie.

The present perfect needs the participle mentido, not the present form: he mentido, not he miento.

✗ *Tú mientes de tus padres.

✓ Correct: Tú mientes a tus padres.

The person lied to takes a: mentir a tus padres, never mentir de tus padres.

Quiz: mentir in use

Ten questions on mentir — its forms, its tenses and its everyday use. Choose the best answer for each one, then check the answer key below, where every answer is explained.

1. Complete the sentence: Tú ______ a tus padres. — "You lie to your parents."

  • a) miento
  • b) mentiste
  • c) mientes
  • d) miente

2. Complete the sentence: Ayer tú ______ a tu madre. — "Yesterday you lied to your mother."

  • a) mentí
  • b) mientes
  • c) mentiste
  • d) mintió

3. Complete the sentence: Nosotros no ______ a nuestros hijos. — "We don't lie to our children."

  • a) mientes
  • b) miento
  • c) mentimos
  • d) mentimos

4. Complete the sentence: Ellos ______ por miedo al castigo. — "They lie out of fear of punishment."

  • a) mientes
  • b) miento
  • c) mienten
  • d) mintieron

5. Which is the correct present tense form of mentir for yo?

  • a) mentimos
  • b) miento
  • c) mientes
  • d) miente

6. Which is the correct present tense form of mentir for tú?

  • a) miente
  • b) miento
  • c) mientes
  • d) mentimos

7. Which is the correct present tense form of mentir for ellos/ellas/Uds.?

  • a) miento
  • b) mienten
  • c) miente
  • d) mientes

8. Which sentence uses mentir correctly?

  • a) Nosotros mentíamos poco, preferimos la verdad.
  • b) Nosotros miente poco, preferimos la verdad.
  • c) Nosotros mentimos poco, preferimos la verdad.

9. What is the past participle of mentir?

  • a) mentido
  • b) mintió
  • c) miento
  • d) mintiendo

10. What does mentir mean in English?

  • a) to have
  • b) to lie
  • c) to go
  • d) to tell the truth

Answer key

  1. c) mientes — The sentence needs the tú form in the present: mientes.

  2. c) mentiste — The sentence needs the tú form in the preterite: mentiste.

  3. c) mentimos — The sentence needs the nosotros/as form in the present: mentimos.

  4. c) mienten — The sentence needs the ellos/ellas/Uds. form in the present: mienten.

  5. b) miento — The present tense form for yo is miento.

  6. c) mientes — The present tense form for tú is mientes.

  7. b) mienten — The present tense form for ellos/ellas/Uds. is mienten.

  8. c) Nosotros mentimos poco, preferimos la verdad. — Nosotros mentimos poco, preferimos la verdad. is correct. The other sentences use the wrong person, the wrong tense, or the wrong pattern for this verb.

  9. a) mentido — The past participle is mentido. You need it for every perfect tense with haber: he mentido, has mentido, ha mentido.

  10. b) to lie — mentir means "to lie".

Frequently asked questions

How do I use mentir in everyday conversation?

Start with the phrases in the examples above — especially the common combinations such as mentir a alguien and decir una mentira. Use the present tense for habits and general facts, and the preterite for things that happened once. Say the sentences aloud until the forms feel automatic, then swap in your own details: your own town, your own family, your own routine.

What is the difference between mentir and decir la verdad?

mentir means "to lie", while decir la verdad means "to tell the truth". They are related words that learners often meet together, but they are not interchangeable — use mentir when you mean "to lie" and decir la verdad when you mean "to tell the truth".

Which tense do I need most with mentir?

The present tense, for habits, routines and general facts — that is where you will use mentir most. The preterite comes next, for things that happened once and ended. The examples on this page use both, plus the imperfect, the future and the present perfect, so you can see the verb across the tenses you actually need.

Is mentir formal or informal?

mentir is neutral — it is used in both formal and informal Spanish, at home, at work and at school. There is no special formal version of it; the same forms work in a conversation with a friend and in a letter to a company. What changes is the situation, not the verb.

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