How to Create and Use Gerunds in French
The French gerund is used with the preposition en. It is equivalent to the English while + -ing, as in while eating (en mangeant); upon + -ing, as in upon arriving (en arrivant); and by + -ing, as in by exercising (en faisant de la gym).
But you have to keep one important thing in mind: The action expressed by the gerund is performed by the same subject as the conjugated verb. For example, to say that Upon arriving, Papa kissed the kids, say: En arrivant Papa a embrassé les enfants.
But if you say: En arrivant les enfants ont embrassé Papa (Upon arriving, the kids kissed Papa), the en arrivant refers to les enfants, not Papa, because the verb embrassé (kissed) is the kids’ action, not Papa’s.
The placement of a gerund in a sentence doesn’t really matter. It can be at the beginning or at the end, and people tend to put it at the end.
En mangeant une pomme j’ai mordu ma lèvre. (While eating an apple, I bit my lip.)
J’ai mordu ma lèvre en mangeant une pomme. (I bit my lip while eating an apple.)
Pronominal verbs have to keep their reflexive pronoun in the gerund, and the pronoun needs to match the subject of the main verb. You place the pronoun between en and the present participle. Use the verb se promener (to take a walk) as an example:
If the subject of the main verb is je, the pronominal verb in the gerund is en me promenant.
If the subject of the main verb is tu, the pronominal verb in the gerund is en te promenant.
If the subject of the main verb is il, elle, on, ils, or elles, the pronominal verb in the gerund is en se promenant.
If the subject of the main verb is nous, the pronominal verb in the gerund is en nous promenant.
If the subject of the main verb is vous, the pronominal verb in the gerund is en vous promenant.
Use the gerund in the following instances:
To express simultaneous actions. For example:
Elle conduit en écoutant la radio. (She drives while listening to the radio.)
Nous prenons une douche en chantant. (We take a shower while singing.)
To answer the question how/why. For example:
Je suis tombé en courant. (I fell because I was running/while running.)
Il gagne sa vie en vendant des hot-dogs. (He earns a living by selling hot dogs.)
To say when something happened. For example:
Elle a crié en voyant la souris. (She screamed upon seeing the mouse.)
Ferme la porte en partant. (Close the door upon leaving.)