Present Indicative: Stem-Changing Verbs (E to I) in Portuguese

In Brazilian Portuguese, some verbs ending in -ir that have an -e- in their stem undergo a vowel change when conjugated in the present indicative tense. The -e- shifts to an -i-. Depending on the verb, this change happens in different grammatical persons. There are two main groups to learn.

Group 1: Change ONLY in the "Eu" (I) form

For a large group of common verbs—such as mentir (to lie), preferir (to prefer), seguir (to follow), sentir (to feel), servir (to serve), vestir (to wear), and conseguir (to manage/be able to)—the stem vowel changes from e to i only in the first-person singular (eu). The rest of the forms keep the original e.

Conjugation of mentir (to lie):

• eu: minto
• tu: mentes
• ele/ela/você: mente
• nós: mentimos
• eles/elas/vocês: mentem

Example Sentences:

• Eu sempre minto quando jogo cartas. (I always lie when I play cards.)
• Ela prefere café sem açúcar. (She prefers coffee without sugar.)
• Eu consigo falar português. (I can speak Portuguese.)

Group 2: Change in ALL stressed positions

A second, smaller group of verbs experiences this e to i shift in all forms where the stem is stressed. This includes the first, second, and third-person singular, as well as the third-person plural. The only form that keeps the e is the first-person plural (nós), because the verbal stress falls on the ending (-imos) rather than the stem.

Verbs in this category include agredir (to attack), prevenir (to prevent), progredir (to progress), and regredir (to regress/go backward).

Conjugation of agredir (to attack):

• eu: agrido
• tu: agrides
• ele/ela/você: agride
• nós: agredimos
• eles/elas/vocês: agridem

Example Sentences:

• Eu me previno contra a gripe todos os anos. (I protect myself against the flu every year.)
• Eles progridem muito rápido no curso. (They progress very fast in the course.)
• A doença regride com o tratamento. (The disease regresses with the treatment.)