A lot of frequently used verbs are irregular in the present tense. Fortunately, most of them are only irregular in the first-person singular form. This will make memorization much easier.
Group #1 – Verbs with a “g” added
These verbs will include a “g” in the first-person singular only, except for “tener” and “venir”.Tener & venir are also stem-changing verb, so their other forms will not be conjugated regularly. This will be discussed further later. For now, just memorize their first-person forms.
| hacer | hago |
| poner | pongo |
| valer | valgo |
| salir | salgo |
| caer | caigo |
| traer | traigo |
| tener | tengo |
| venir | vengo |
Example: | |
| hacer (to do, to make) | |
| hago | hacemos |
| haces | hacéis |
| hace | hacen |
Group #2 – Verbs that add “z” before “c”
Most verbs that end in either “cer” or “cir” are irregular in the present. They will add a “z” before the “c” only in the first-person singular. All other forms are conjugated regularly.
| agradecer | agradezco |
| aparecer | aparezco |
| conocer | conozco |
| crecer | crezco |
| merecer | merezco |
| nacer | nazco |
| parecer | parezco |
| conducir | conduzco |
| introducir | introduzco |
| producir | produzco |
| traducir | traduzco |
Example: | |
| conocer (to know, be familiar with) | |
| conozco | conocemos |
| conoces | conocéis |
| conoce | conocen |
Group #3 – Verbs where “z” replaces the “c”
If a verb ends in a consonant followed by either “cer” or “cir”, a “z” replaces the “c” only in the first-person singular.
| convencer | convenzo |
| ejercer | ejerzo |
| vencer | venzo |
Example: | |
| convencer (to convince) | |
| convenzo | convencemos |
| convences | convencéis |
| convence | convencen |
Group #4 – Verbs where “g” changes to “j”
If a verb ends in either “ger” or “gir”, the “g” will change to a “j” only in the first-person singular.
| coger | cojo |
| escoger | escojo |
| proteger | protojo |
| corregir | corrijo |
| exigir | exijo |
Example: | |
| exigir (to demand) | |
| exijo | exigimos |
| exiges | exigéis |
| exige | exigen |
Group #5 – Verbs that add a “y”
Verbs that end in “uir” that aren’t preceded by a “g”, will add a “y” in the stem, so that there won’t be 3 vowels in a row. This will be done in all forms except for nosotros & vosotros.
| concluir | concluyo, concluyes, concluye, concluyen |
| construir | construyo, construyes, construye, construyen |
| contribuir | contribuyo, contribuyes, contribuye, contribuyen |
| incluir | incluyo, incluyes, incluye, incluyen |
Example: | |
| contribuir (to contribute) | |
| contribuyo | contribuimos |
| contribuyes | contribuís |
| contribuye | contribuyen |