c'est-à-dire
B1that is to say, i.e., in other words
Used to clarify, explain, or reformulate what was just said. Very useful for making your meaning clearer or more precise.
Usage
Can be abbreviated as 'c.-à-d.' in writing. Often used to provide a more specific explanation or example of a general statement.
Examples
J'arrive demain, c'est-à-dire le 15 mars.
I'm arriving tomorrow, that is to say March 15th.
Context: Clarifying a date
Il est bilingue, c'est-à-dire qu'il parle deux langues couramment.
He's bilingual, that is to say he speaks two languages fluently.
Context: Explaining a term
Je travaille à mi-temps, c'est-à-dire 20 heures par semaine.
I work part-time, i.e. 20 hours per week.
Context: Being more specific
Synonyms & Alternatives
Important Notes
Very useful connector for clarifying your meaning. Common in both spoken and written French.