It depends how demi is used: as an invariable prefix or an adjective:
Une demi-heure plus tard. -- (invariable prefix)
Une heure et demie plus tard. -- (adjective, which requires matching to "heure")
The same goes for grand-mère.
It depends how demi is used: as an invariable prefix or an adjective:
Une demi-heure plus tard. -- (invariable prefix)
Une heure et demie plus tard. -- (adjective, which requires matching to "heure")
The same goes for grand-mère.
Don't have an account yet? Join today
Test your French to the CEFR standard
Find your French level