Past Participle: Class I (-at)

The past participle is the part of the perfect compus that carries the verb's meaning — and for Class I verbs (the huge group ending in -a), it is the easiest thing in Romanian grammar. You take the infinitive, drop the final -a, and add -at. That is the whole rule, and it has no exceptions across the entire class: a cânta → cântat, a lucra → lucrat, a întreba → întrebat. Because Class I is by far the largest and most productive group — almost every borrowed or newly coined verb joins it — mastering this single pattern unlocks thousands of past forms at once. The only subtlety worth your attention is not the formation but the participle's double life: invariable in the perfect, but agreeing like an adjective elsewhere.

The rule: -a → -at

Drop the infinitive's final -a, add -at:

The -ez verbs follow the same rule

Some Class I verbs take the -ez- infix in the present (a dansa → eu dansez), which sometimes makes learners expect a special past form. It is not special at all: the participle ignores the infix entirely and follows the plain -at rule. A dansa → dansat, a lucra (no infix) → lucrat, a forma → format — the infix lives only in the present, never in the participle.

In the perfect: invariable

Inside the perfect compus, the -at participle is frozen. It never changes for the subject's gender or number — only the auxiliary moves. A woman, a man, a crowd: all say cântat.

Its second life: as an adjective, it agrees

Here is the one thing to watch. The very same participle can also function as an adjective ("a sung melody," "the learned lesson"), and then it agrees in gender and number with the noun it modifies, exactly like any Romanian adjective: cântat / cântată / cântați / cântate.

So the same word behaves in two opposite ways: invariable when it builds the past (Maria a cântat), but agreeing when it describes a noun (o melodie cântată). Keeping these two roles separate is the entire trick of the participle — and it is the seed of the passive voice (Melodia a fost cântată de copii — the melody was sung by children), which you will meet later and where the agreeing form returns.

A third role: the supine (de + participle)

The same -at form also appears after the preposition de in the supine, a noun-like construction meaning "to be done / for doing." Here, just as in the perfect, it stays invariable — it is not describing any noun's gender, so nothing triggers agreement.

You do not need to master the supine now; the point is simply that the bare -at form turns up in three places — the perfect (invariable), the supine (invariable), and the adjective/passive (agreeing) — and that agreement only ever appears in the third. Recognizing the form in all three keeps you from second-guessing whether to add a gender ending.

Common Mistakes

This is the mirror image of the adjective rule: learners who know o melodie cântată over-apply the agreement and write a cântată in the perfect. Inside the perfect, it is always the bare cântat.

Key Takeaways

• Class I participle: drop infinitive -a, add -at — a cânta → cântat. No exceptions in the whole class.
• The -ez- infix verbs follow the same rule (a dansa → dansat); the infix never reaches the participle.
• In the perfect compus the participle is invariable (Maria a cântat).
• As an adjective the same word agrees (o melodie cântată), which is also the form used in the passive.
• The one thing to watch is this dual behavior — decide whether the participle is building a tense (invariable) or describing a noun (agreeing).