Group 1 stem change: é → è (préférer)
Summary
Verbs like préférer change the é of the last stem syllable to è before a silent ending, so the stressed vowel opens: je préfère but nous préférons.
Explanation
A group of regular -er verbs carries an é (accent aigu) in the final syllable of the stem: préférer, espérer, répéter, célébrer, considérer, posséder, protéger, suggérer. When the ending is silent, that é opens to an è (accent grave) because the syllable becomes stressed: je préfère, tu préfères, il/elle/on préfère, ils/elles préfèrent. The endings themselves are the ordinary -er endings; only the accent on the stem vowel changes.
The nous and vous forms keep the é, because there the ending (-ons, -ez) is pronounced and the stem syllable is no longer the last sounded one: nous préférons, vous préférez. So a single verb shows both spellings within the present: je préfère / nous préférons, j'espère / vous espérez, il répète / nous répétons. The change reflects pronunciation: è is the open [ɛ] you hear in the singular and 3rd-plural forms.
These verbs are used constantly — préférer, espérer, répéter and célébrer are everyday vocabulary — so the alternation is worth automating early. It mirrors the e → è pattern of acheter or lever (an open è before a silent ending); the only difference is the starting point: here the stem already has an é that shifts to è, rather than a mute e that gains an accent.
There is one classic subtlety in the future and the conditional. Traditional spelling KEEPS the é throughout these tenses, even though the vowel is pronounced [ɛ]: je préférerai, je préférerais, il espérera. This is the point on which préférer differs from acheter (which writes j'achèterai with è). The 1990 spelling reform now also allows the phonetic je préfèrerai, but the classic je préférerai remains fully correct and is what most exams expect.
Rule of thumb: when an -er verb has é in its last stem syllable, change it to è in the four present forms with a silent ending (je, tu, il/elle/on, ils/elles) and keep é in nous/vous — but in the future and conditional, traditional spelling keeps é throughout (je préférerai).
Examples
Je préfère le thé, mais nous préférons le café le matin. — I prefer tea, but we prefer coffee in the morning. (je préfère takes è (silent ending); nous préférons keeps é.)
Ils espèrent réussir l'examen. — They hope to pass the exam. (espérer → ils espèrent, with è in the 3rd-person plural.)
Tu répètes la phrase et nous répétons après toi. — You repeat the sentence and we repeat after you. (Same verb, both spellings: tu répètes (è) vs nous répétons (é).)
Nous célébrons son anniversaire demain. — We are celebrating his birthday tomorrow. (In the nous form the é stays: célébrons.)
Je préférerai partir tôt si je peux. — I will prefer to leave early if I can. (Traditional spelling keeps é in the future: je préférerai (the 1990 reform also allows je préfèrerai).)
Common mistakes
Elle préfére le thé.
Elle préfère le thé.
Verbs like préférer change the é of the stem's last syllable to è whenever the ending that follows is silent, as in the il/elle form. Préfére keeps the wrong accent (é); the silent -e ending requires the open è: préfère.
Prerequisites
Related rules
stem-changepresent-tenseorthography