Fortalecer Examples, Sentences and Quiz in Spanish

fortalecer means to strengthen, and it is a verb you will meet in everyday Spanish again and again. Fortalecer means to strengthen, and it covers strengthening muscles with exercise, strengthening a friendship and strengthening a team or an economy. It is the opposite of debilitar, and it is a -cer spelling-change verb. This page puts fortalecer to work: twelve example sentences in different tenses and persons, grouped by use, then two short dialogues where the verb appears naturally, then the common mistakes to avoid, and finally a ten-question quiz with explained answers. Every Spanish form on this page comes from the verified conjugation tables for fortalecer, and the full tables are on the fortalecer conjugation page if you need to check a form.

Example sentences

Everyday uses

  1. Yo fortalezco los músculos con ejercicio. — I strengthen the muscles with exercise.
  2. Él fortalece la amistad con los años. — He/she strengthens the friendship over the years.
  3. Ayer, yo fortalecí el equipo con dos fichajes. — Yesterday, I strengthened the team with two signings.
  4. Antes, nosotros fortalecíamos la economía del país. — Before, we used to strengthen the country's economy.

In other tenses

  1. Mañana, tú fortalecerás los músculos con ejercicio. — Tomorrow, you will strengthen the muscles with exercise.
  2. Yo fortalecería la amistad con los años. — I would strengthen the friendship over the years.
  3. Él ha fortalecido el equipo con dos fichajes. — He/she has strengthened the team with two signings.
  4. Espero que él fortalezca la economía del país. — I hope he/she strengthens the country's economy.

With other people

  1. Nosotros fortalecemos los músculos con ejercicio. — We strengthen the muscles with exercise.
  2. Vosotros fortalecéis la amistad con los años. — You all strengthen the friendship over the years.
  3. Antes, ellos fortalecían el equipo con dos fichajes. — Before, they used to strengthen the team with two signings.
  4. Mañana, él fortalecerá la economía del país. — Tomorrow, he/she will strengthen the country's economy.

Fortalecer in context

Two short dialogues that use fortalecer the way people really use it. Read them aloud — the verb forms will stick much faster in a conversation than in a table.

Dialogue 1: today and yesterday

  • Ana: "Hola, ¿qué tal?" — "Hello, how are you?"
  • Luis: "Hoy fortalezco los músculos con ejercicio." — "Today I strengthen the muscles with exercise."
  • Ana: "¿Y ayer?" — "And yesterday?"
  • Luis: "Ayer, fortalecí el equipo con dos fichajes." — "Yesterday I strengthened the team with two signings."
  • Ana: "¿Y mañana, tú fortalecerás la amistad con los años?" — "And tomorrow, will you will strengthen the friendship over the years?"
  • Luis: "Sí, claro. Y tú también." — "Yes, of course. And you too."

Dialogue 2: making plans

  • Marta: "Mañana, nosotros fortalecemos la economía del país." — "Tomorrow we strengthen the country's economy."
  • Carlos: "Perfecto. Yo fortalecería la amistad con los años si tuviera más tiempo." — "Perfect. I would would strengthen the friendship over the years if I had more time."
  • Marta: "Espero que él fortalezca los músculos con ejercicio." — "I hope he strengthens the muscles with exercise."
  • Carlos: "Seguro que sí. Él ya ha fortalecido el equipo con dos fichajes." — "Surely. He has already has strengthened the team with two signings."
  • Marta: "Vale, nos vemos mañana." — "OK, see you tomorrow."

Notice how the same verb changes with the tense: the present for the plan, the conditional for the wish, the subjunctive after espero que, and the present perfect for what has already happened. That is the whole point of learning a verb across its tenses, not just in one form.

Common mistakes

  1. Wrong: Yo fortalece los músculos con ejercicio. — Right: Yo fortalezco los músculos con ejercicio. — The person matters: fortalece is the él/ella/Ud. form, while the yo form is fortalezco. Using the third-person form with yo is one of the most common beginner errors.
  2. Wrong: Yo fortaleco la amistad con los años. — Right: Yo fortalezco la amistad con los años. — In the present, the correct first-person form is fortalezco, not fortaleco. fortalecer is a spelling-change verb: c becomes zc before o and a, so the written form changes to keep the same sound. The regular-looking form is wrong.
  3. Wrong: Treating fortalecer and debilitar as identical in every context. — Right: Fortalecer means to strengthen, while debilitar means to weaken, its opposite. — They overlap, but each has uses the other does not: fortalecer fits sentences such as Fortalezco los músculos con ejercicio, while debilitar belongs in a different sentence. Check the meaning you want before choosing.
  4. Wrong: Yo soy fortalecido la amistad con los años. — Right: Yo he fortalecido la amistad con los años. — Spanish perfect tenses use haber, not ser: he fortalecido, has fortalecido, ha fortalecido. Ser plus the participle makes a passive, not a perfect tense.
  5. Wrong: De niño, yo fortalecí el equipo con dos fichajes todos los días. — Right: De niño, yo fortalecía el equipo con dos fichajes todos los días. — For a repeated habit in the past, use the imperfect (fortalecía), not the preterite. The preterite (fortalecí) is for one finished action.

Quiz: test yourself

Ten questions on fortalecer: four on the forms, three on the meaning, and three on spotting the correct sentence. Check the answer key below.

  1. Complete the sentence: Yo ___ los músculos con ejercicio. (present tense) A. fortalezco B. fortaleces C. fortalece D. fortalecemos

  2. Complete the sentence: Él ___ la amistad con los años. (preterite tense) A. fortalecí B. fortaleciste C. fortalecimos D. fortaleció

  3. Complete the sentence: Tú ___ el equipo con dos fichajes. (future tense) A. fortalecerá B. fortaleceremos C. fortalecerás D. fortaleceré

  4. Complete the sentence: Nosotros ___ la economía del país. (imperfect tense) A. fortalecíais B. fortalecíamos C. fortalecía D. fortalecías

  5. What does "Yo fortalezco los músculos con ejercicio." mean in English? A. I strengthen the muscles with exercise. B. I strengthen the friendship over the years. C. I strengthen the team with two signings. D. I strengthen the country's economy.

  6. What does "Él fortaleció la amistad con los años." mean in English? A. He/she strengthened the muscles with exercise. B. He/she strengthened the team with two signings. C. He/she strengthened the country's economy. D. He/she strengthened the friendship over the years.

  7. What does "Nosotros fortaleceremos el equipo con dos fichajes." mean in English? A. We will strengthen the friendship over the years. B. We will strengthen the country's economy. C. We will strengthen the team with two signings. D. We will strengthen the muscles with exercise.

  8. Which sentence is correct? A. Yo fortaleco la amistad con los años. B. Yo fortalece la amistad con los años. C. Yo fortalezco la amistad con los años.

  9. Which sentence is correct? A. Él fortalecí el equipo con dos fichajes. B. Él fortaleció el equipo con dos fichajes. C. Él fortalecieron el equipo con dos fichajes.

  10. Which sentence is correct? A. Espero que yo fortalezca la economía del país. B. Yo fortaleca la economía del país. C. Yo fortalezca la economía del país.

Answer key

  1. fortalezco — The yo present form of fortalecer is fortalezco.
  2. fortaleció — The el preterite form of fortalecer is fortaleció.
  3. fortalecerás — The tu future form of fortalecer is fortalecerás.
  4. fortalecíamos — The nosotros imperfect form of fortalecer is fortalecíamos.
  5. I strengthen the muscles with exercise. — The Spanish sentence uses the present form fortalezco, so the English is "I strengthen the muscles with exercise." The other options use a different object or situation.
  6. He/she strengthened the friendship over the years. — The Spanish sentence uses the preterite form fortaleció, so the English is "He/she strengthened the friendship over the years." The other options use a different object or situation.
  7. We will strengthen the team with two signings. — The Spanish sentence uses the future form fortaleceremos, so the English is "We will strengthen the team with two signings." The other options use a different object or situation.
  8. Yo fortalezco la amistad con los años. — The correct sentence is "Yo fortalezco la amistad con los años." The other sentences use the wrong form or the wrong person for the subject.
  9. Él fortaleció el equipo con dos fichajes. — The correct sentence is "Él fortaleció el equipo con dos fichajes." The other sentences use the wrong form or the wrong person for the subject.
  10. Espero que yo fortalezca la economía del país. — The correct sentence is "Espero que yo fortalezca la economía del país." The other sentences use the wrong form or the wrong person for the subject.

Frequently asked questions

What does fortalecer mean, and when do I use it?

Fortalecer means to strengthen. Fortalecer means to strengthen, and it covers strengthening muscles with exercise, strengthening a friendship and strengthening a team or an economy. It is the opposite of debilitar, and it is a -cer spelling-change verb. A good first sentence to remember is Yo fortalezco los músculos con ejercicio. — "I strengthen the muscles with exercise."

What is the difference between fortalecer and debilitar?

Fortalecer means to strengthen, while debilitar means to weaken, its opposite. They appear in similar situations, but they are not interchangeable: use fortalecer when you mean to strengthen, as in Yo fortalezco la amistad con los años., and use debilitar for to weaken, its opposite.

How do I say "I strengthen" in the past?

For one finished action, use the preterite: Yo fortalecí la amistad con los años.. For a repeated habit or background in the past, use the imperfect: Yo fortalecía el equipo con dos fichajes.. For something that has just happened, use the present perfect: Yo he fortalecido la amistad con los años..

How do I practise fortalecer?

Start with the fortalecer conjugation page for the full tables, then the fortalecer in the present tense page for the tense in focus, and use the Spanish Verb Quiz to test the forms under pressure. Spelling change: c becomes zc before o and a, so yo fortalezco and the subjunctive fortalezca.

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