Here's a breakdown:
* être: This is the verb "to be" in French.
* troisième personne: This means "third person," which refers to the person or thing being spoken about.
* singulier: This means "singular," indicating that the subject is one person or thing.
Therefore, "être à la troisième personne du singulier" means "to be in the third person singular."
The third-person singular form of "être" is "est."
Examples:
* Il est grand. (He is tall.)
* Elle est belle. (She is beautiful.)
* Le chat est gris. (The cat is gray.)
Essentially, "être à la troisième personne du singulier" is a grammatical concept used to describe the conjugation of the verb "être" for a singular subject that is not the speaker or the listener.