Verb + (à / de) + infinitive

Summary

When one verb governs another, French uses three fixed patterns — a direct infinitive (vouloir partir), verb + à + infinitive (commencer à faire) and verb + de + infinitive (décider de faire) — and which one applies is a lexical property of the first verb.

Explanation

Very often a conjugated verb is followed by a second verb in the infinitive: je veux dormir, j'aime voyager. French never puts that second verb into a conjugated form here — it stays an infinitive — but it does require you to know whether a preposition links the two verbs, and if so which one. There are exactly three patterns, and the first verb decides which.

Pattern one: direct infinitive, with no preposition at all. This covers the modal and 'wish/motion/preference' verbs: vouloir, pouvoir, devoir, savoir, aller, venir (in motion sense), aimer, adorer, détester, préférer, espérer, falloir (il faut). So: je dois travailler, elle sait nager, nous allons partir, ils espèrent gagner. Adding a preposition here ('je veux à partir') is wrong.

Pattern two: verb + à + infinitive. The preposition à often carries a nuance of direction, goal or gradual engagement. Common members are commencer à, se mettre à, apprendre à, réussir à, arriver à, aider à, hésiter à, continuer à, chercher à, penser à and inviter quelqu'un à. So: il a commencé à pleuvoir, j'apprends à conduire, elle a réussi à finir.

Pattern three: verb + de + infinitive. This is the largest group and includes finir de, arrêter de, essayer de, décider de, oublier de, refuser de, choisir de, accepter de, promettre de, éviter de, venir de (recent past), and être content/heureux/obligé de. So: j'ai décidé de rester, n'oublie pas de fermer la porte, il a refusé de répondre. Note that a few verbs allow both (commencer à / de, continuer à / de) with little change of meaning.

The choice is lexical, not logical: it is part of each verb's dictionary entry and cannot be reasoned out from the meaning, so it must be memorised verb by verb. The same surface meaning can take different prepositions (réussir à faire but parvenir à faire, yet finir de faire), and English gives no clue, since English uses 'to' or '-ing' indifferently. Two frequent errors are inserting a preposition after a direct-infinitive verb and dropping the required à or de.

Rule of thumb: learn the linking preposition together with the verb, as a single chunk — 'commencer-à', 'décider-de', 'vouloir-∅'. When unsure, recall a fixed phrase you already know with that verb and copy its pattern; if you cannot, default to checking a dictionary rather than guessing.

Examples

Je veux apprendre le français. — I want to learn French. (Direct infinitive: vouloir takes no preposition.)

Il a commencé à pleuvoir vers midi. — It started to rain around noon. (Verb + à + infinitive: commencer à.)

Nous avons décidé de partir plus tôt. — We decided to leave earlier. (Verb + de + infinitive: décider de.)

Elle apprend à jouer du piano. — She is learning to play the piano. (à signals the goal/skill being acquired (apprendre à).)

N'oublie pas de fermer la porte. — Don't forget to close the door. (oublier de + infinitive; dropping de would be an error.)

Tu devrais essayer de te reposer un peu. — You should try to rest a little. (Two patterns chained: devoir (direct) + essayer de (de).)

Common mistakes

Related rules

• Prepositions à and de
• Causative faire (faire + infinitive)
• Pronominal (reflexive) verbs