Prepositions à and de
Summary
À marks destination, location and the indirect object ('to/at'); de marks origin, possession and material ('from/of'). Both fix verb constructions and both contract with le/les into au/aux and du/des.
Explanation
À and de are the two workhorse prepositions of French. Broadly, à points toward a goal — destination, location or recipient: aller à Paris (go to Paris), être à la maison (be at home), parler à Marie (speak to Marie). De points away from or back to a source — origin, possession, content or material: venir de Lyon (come from Lyon), la voiture de Paul (Paul's car), une tasse de café (a cup of coffee), une table de bois (a wooden table). A first approximation is à = 'to/at', de = 'from/of'.
Both prepositions are also grammatical glue that links a verb to its complement, and here the choice is fixed by the verb, not by meaning. Some verbs govern à (commencer à faire, apprendre à nager, réussir à finir, penser à quelqu'un), others govern de (finir de manger, décider de partir, essayer de comprendre, parler de quelque chose). Because the pattern is lexical, you should learn each verb together with its preposition, exactly as you learn its meaning.
Verbs of motion split neatly: aller à (go to) versus venir de (come from), and likewise arriver à / partir de. This pair also drives the pronouns y and en: y replaces à + place (j'y vais = I'm going there) and en replaces de + thing (j'en viens = I'm coming from there / I have some of it). Recognising the à / de behind a verb therefore helps you choose the right pronoun later.
The single most important mechanical point is contraction with the definite article. À + le becomes au and à + les becomes aux; de + le becomes du and de + les becomes des. These contractions are obligatory: « je vais à le marché » and « je reviens de le bureau » are simply wrong — say je vais au marché, je reviens du bureau. Crucially, à la, à l', de la and de l' do NOT contract, because la and l' are not le or les: je vais à la gare, la porte de l'école.
Rule of thumb: ask whether you mean a goal/location (à) or a source/belonging (de) for ordinary phrases; for verb + infinitive or verb + noun, trust the memorised construction rather than translating the English preposition. Then run the contraction check: if à or de is immediately followed by le or les, fuse them into au/aux or du/des; leave la and l' untouched.
Examples
Je vais au marché et je reviens du bureau. — I'm going to the market and coming back from the office. (au = à + le; du = de + le (obligatory contractions).)
C'est le livre de Marie. — It's Marie's book. (de expresses possession (the book of Marie).)
Il a commencé à travailler à huit heures. — He started working at eight o'clock. (commencer à + infinitive (fixed verb construction); à for clock time.)
Nous avons décidé de partir demain. — We decided to leave tomorrow. (décider de + infinitive — the preposition belongs to the verb.)
Je vais à la gare, près de l'hôtel. — I'm going to the station, near the hotel. (à la and de l' do not contract (only le/les do).)
Veux-tu une tasse de thé ? — Would you like a cup of tea? (de links a container/quantity to its content (a cup of tea).)
Common mistakes
J'ai commencé de travailler et je vais finir à manger.
J'ai commencé à travailler et je vais finir de manger.
Many French verbs require a fixed preposition before a following infinitive, and à and de are not interchangeable. Some verbs take à (commencer à, apprendre à, réussir à, aider à), others take de (finir de, décider de, essayer de, oublier de), and a few take neither (vouloir, pouvoir, devoir + bare infinitive). The choice is lexical, not logical, so it must be learned with each verb. A frequent error is swapping them, as in « commencer de » or « finir à »; the standard forms are commencer à faire and finir de faire. When in doubt, treat the preposition as part of the verb's dictionary entry.
Prerequisites
Related rules
prepositionsverb-complementscontractions