Verbs followed by à or de + infinitive

Elle commence à travailler à huit heures, mais elle a décidé de partir plus tôt aujourd'hui.She starts working at eight, but she decided to leave earlier today.

When one verb is directly followed by a second verb in the infinitive, French sometimes links them with nothing at all, sometimes with à, and sometimes with de. The choice depends on the first verb, in the sense it's being used with — for most verbs it's one fixed pattern you can rely on every time, but a few verbs genuinely shift pattern along with a shift in meaning (more on that below). There's no single logical rule that predicts the pattern perfectly, but a few groupings cover most of the common verbs, which makes the rest much easier to remember.

A useful shortcut: learn the preposition together with the verb, as one unit — commencer à, décider de, aimer (no preposition) — the same way you'd learn a verb's gender-linked noun form.

No preposition at all

A large, high-frequency group links straight to the infinitive with nothing in between: the modal verbs vouloir, pouvoir, devoir, savoir; verbs of preference like aimer, détester, préférer; aller, which builds the futur proche (see futur proche); and a handful of others including espérer, falloir, laisser, faire (the causative — see faire + infinitive), and verbs of perception like voir and entendre. See also modal verbs: devoir, pouvoir, vouloir for more on that group specifically.

• Je veux partir. (I want to leave.)
• Nous aimons voyager. (We like to travel.)
• Elle va arriver bientôt. (She's going to arrive soon.)
• J'espère réussir. (I hope to succeed.)

À + infinitive

A second large group needs à before the infinitive. Many describe starting, continuing, learning, managing, or getting used to something — a loose semantic thread, not a strict rule:

• Elle a commencé à apprendre le russe. (She started learning Russian.)
• Il a réussi à finir à temps. (He managed to finish on time.)
• Je t'aide à préparer le dîner. (I'm helping you prepare dinner.)

De + infinitive

A third group needs de. This one leans toward finishing, stopping, deciding, choosing, forgetting, refusing, and similar verbs of a mental or completed act:

• J'ai décidé de partir plus tôt. (I decided to leave earlier.)
• Elle a fini de manger. (She finished eating.)
• Il a oublié de fermer la porte. (He forgot to close the door.)

Être content, avoir peur, avoir envie, and similar adjective/noun expressions with être or avoir follow the same de pattern as the de-verbs above — it's not just bare verbs that take a preposition before an infinitive.

The same verb, two prepositions, two meanings

A few common verbs genuinely change meaning depending on the preposition, so the preposition itself carries information here rather than being arbitrary:

• penser à (to think about, have in mind) vs. penser + infinitive with no preposition (to plan/intend to): Je pense à partir (it's crossed my mind) vs. Je pense partir demain (I intend to leave tomorrow, closer to a decision).
• venir de + infinitive (to have just done something) vs. venir + infinitive with no preposition (to come and do something): Elle vient de partir (she just left) vs. Elle vient dîner (she's coming to have dinner) — see venir de for the full "just did" construction.
• manquer de + infinitive (to almost/narrowly do something, not "to lack" — manquer de + a noun means "to lack") vs. manquer à + person (to be missed by someone, with no infinitive at all): Il a manqué de tomber (he almost fell) is a completely different construction from Tu me manques (I miss you, literally "you are lacking to me").

Common mistakes

• ❌ J'ai décidé partir. → ✅ J'ai décidé de partir. (décider needs de — dropping it is one of the most frequent errors with this group)
• ❌ Elle a commencé de travailler. → ✅ Elle a commencé à travailler. (commencer takes à, not de — the two prepositions aren't interchangeable even though English uses just "to" for both)
• ❌ Je veux à partir. → ✅ Je veux partir. (vouloir takes no preposition at all — adding one is as wrong as dropping a required one)
• ❌ Il a réussi partir. → ✅ Il a réussi à partir. (réussir needs à — the infinitive can't attach directly)

Quick check

Key takeaways

• Some verbs (vouloir, pouvoir, devoir, aimer, aller, espérer...) link straight to the infinitive with no preposition.
• Some (commencer, continuer, apprendre, réussir, aider...) need à.
• Some (décider, finir, arrêter, oublier, essayer...) need de, and this includes many être/avoir + adjective/noun expressions like avoir envie de.
• The preposition belongs to the first verb's specific sense or construction, not the verb in the abstract — learn it together with the verb, the same way you'd learn a noun's gender.
• A few verbs (penser, venir) genuinely shift meaning depending on which preposition (or none) follows — and manquer de + infinitive ("almost do") is a different construction entirely from manquer à + person ("be missed by").