The e → ie Stem Change

In a small set of high-frequency Italian verbs, the stem vowel e turns into ie when the stress falls on it. Where the stress shifts off the stem (in noi and voi), the e stays as e. The result is a paradigm where the same verb appears with two stems — one for the rhizotonic (root-stressed) forms, one for the rest.

This page does three things: it shows the pattern, lists exactly which verbs follow it (the list is closed and short), and explains why nearby look-alike verbs do not undergo the shift.

The pattern

Stress falls on the root in io, tu, lui/lei, and loro. Stress falls on the ending in noi and voi. Where the root is stressed, e → ie. Where it isn't, e stays e.

The pattern produces a 1-2-3, gap, gap, 6 shape: four forms with the diphthong, two without. This is the same shape you see in the -isco subgroup (where the gap is in noi and voi) and in the -g- insertion pattern. Italian recycles this 4+2 shape across multiple irregularities.

Sedere — to sit

Sedere is the cleanest example: the stem sed- alternates with sied- depending on stress, with no other changes.

Notice: in spoken Italian, the reflexive form sedersi is far more common than plain sedere. You'll hear mi siedo, ti siedi, si siede, ci sediamo, vi sedete, si siedono far more often than the bare verb.

Tenere — to hold, keep

Tenere combines the e → ie shift with the -g- insertion pattern. The result is one of Italian's most distinctive paradigms.

The io and loro forms have -g- without -ie- (because the -g- insertion absorbs the slot where the diphthong would have appeared — tengo /ˈtɛŋ.go/ has /ɛ/, not /jɛ/). The tu, lui, lei forms show the -ie- shift cleanly. The noi and voi forms keep plain e.

This pattern extends to all compounds of tenere: mantenere, ottenere, sostenere, contenere, appartenere, intrattenere, ritenere. Conjugate them by analogy.

Venire — to come

Venire works the same way: the io and loro forms get -g- (vengo, vengono), while the tu, lui, lei forms show the diphthong -ie- (vieni, viene). The noi and voi forms keep plain e (veniamo, venite).

For the full treatment of venire's deictic semantics — when to use it versus andare — see the venire page. For the -g- side of the irregularity, see the -g- insertion pattern.

The closed list

The verbs that take the e → ie shift in the presente indicativo are these:

Memorize this list. Outside it, no verb undergoes the e → ie shift in modern Italian. The pattern is closed: it does not extend to new verbs, and you cannot apply it by analogy.

Why these verbs and not others

The historical reason: in Latin, a short e (Latin e, in contrast to long ē) diphthongized to ie under stress in the open syllable. So Latin vĕnit > Italian viene; tĕnet > tiene; sĕdet > siede. The diphthong stayed because Italian preserved the stress-conditioned alternation; the plain e survived where the syllable was unstressed. This is why the same root shows up two ways in the same verb's paradigm.

But the rule is closed because Latin's vowel-length distinction collapsed into the modern Italian system. Modern Italian doesn't apply this sound change to new words — it's preserved only in the verbs that inherited it directly from Latin. So credere (Latin credo, with long ē) does not diphthongize: credo, credi, crede, crediamo, credete, credono, all with plain e. Compare:

You don't have to learn the Latin to use Italian, of course — the practical lesson is just that most -ere verbs do not take the shift, and you should memorize the small closed list above as the exceptions.

Verbs that look similar but DON'T diphthongize

This is where most learners go wrong. Several common verbs have e in their stem but do not undergo the shift. They keep plain e throughout the conjugation.

Compare the cleanly contrasting pair tenere vs credere:

The endings are identical (-o, -i, -e, -iamo, -ete, -ono). What differs is the stem vowel.

Sentire — does NOT diphthongize, despite looking like it should

A particularly tricky case: sentire ("to hear, to feel") has an e in its stressed root and is an -ire verb, like venire. But sentire does not diphthongize:

Same family, same vowel in the infinitive — completely different paradigm. The historical explanation is again the Latin vowel: sentire came from Latin sĕntīre, but the diphthongization rule applied differently in this verb due to the consonant cluster. The result for the modern learner: just memorize sento, not siento.

Where else the shift matters

The e → ie alternation isn't unique to the presente. It also shows up in:

• The presente congiuntivo (subjunctive present): che io tenga, che tu tenga, che lui tenga, che noi teniamo, che voi teniate, che loro tengano. Same 4+2 pattern.
• The imperativo (imperative): tieni! (tu form, with the diphthong); teniamo! (noi, no diphthong); tenete! (voi, no diphthong).
• The imperative-derived expressions: fixed phrases like vieni qui! ("come here!") or tieni! ("here you go" — handing something over) preserve the stressed diphthongized shape, since the imperative tu form is rhizotonic.

In the imperfetto, futuro, and condizionale, the e stays plain throughout (tenevo, terrò, terrei; venivo, verrò, verrei) — those tenses don't have the rhizotonic vs ending-stressed alternation.

Spanish speakers' shortcut and trap

Spanish has a similar pattern (Spanish tener > tengo, tienes, tiene, tenemos, tenéis, tienen; venir > vengo, vienes, viene, venimos, venís, vienen). The match is close enough that Spanish speakers transfer the pattern correctly to Italian most of the time.

The trap: Spanish extends the pattern to a few more verbs than Italian does. Pensar in Spanish (pienso, piensas...) has no Italian counterpart with the shift — Italian pensare is regular: penso, pensi, pensa, pensiamo, pensate, pensano. Spanish speakers must un-learn their instinct to diphthongize pensare.

For the related o → uo shift, see stem change o → uo.

Common mistakes

Key takeaways

The e → ie alternation is a small, closed-list irregularity that affects high-frequency verbs in the presente indicativo.

Three points to internalize:

1. The shift is stress-conditioned. Where the stress falls on the root (io, tu, lui/lei, loro), e → ie. Where the stress falls on the ending (noi, voi), e stays e.

2. The list is short. Tenere and its compounds, venire and its compounds, sedere/possedere/risiedere. That's it. Most -ere and -ire verbs with e in their stem (credere, vedere, sentire, prendere, leggere) do not undergo the shift.

3. In tenere and venire, the shift coexists with -g- insertion. Io and loro have -g- (without -ie-): tengo, tengono, vengo, vengono. Tu, lui, lei have -ie- (without -g-): tieni, tiene, vieni, viene. Noi and voi have neither.

To see this pattern at work in a single high-frequency verb, study venire. For the related -g- irregularity that often accompanies it, see the -g- insertion pattern. For the parallel o → uo shift in another small set of verbs, see stem change o → uo.