Learn French: J'ai arrosé leur potager pendant un mois. - I watered their vegetable garden for a month.

In French, pendant is used to express the duration of an action that has a clear beginning and end in the past. English speakers often want to use pour for 'for', but in French, pour with time usually indicates a scheduled duration for a future event (like 'I am leaving for a month'). Since this action is already completed, pendant is the correct choice.

Why use the passé composé (J'ai arrosé) rather than the imperfect tense if the action lasted a whole month?

Even though the watering happened over a long period, it has a specified, completed duration (pendant un mois). The passé composé is used for past events with a clear start and end. If you used the imperfect tense (j'arrosais), it would sound like an open-ended habit, meaning 'I used to water their garden'.

Why is it leur potager and not leurs if 'their' implies multiple owners?

In French, possessive adjectives match the noun being owned, not the number of owners. Because there is only one vegetable garden (le potager), you must use the singular leur. If they owned multiple vegetable gardens, you would use the plural leurs potagers.

What is the difference between un potager and un jardin?