“Être à tu et à toi” is a French expression that translates literally to “to be at you and you”. The meaning in English is as follows:
- to be on a first name basis with somebody
- to be good friends
A French definition on expressio.fr is “to be close or informal”. In French there are two ways of saying you: tu and vous. Tu is considered informal and vous is considered formal. Hence, “être à tu et à toi” is to use the informal “tu” with somebody.
Here’s an example sentence:
- Quand j’étais a l’université j’étais à tu et toi avec mes profs: on se connaissait bien et discutait souvent après les cours. When I was in university I was on a first-name basis with my professors. We knew each other well and chatted often after class.
Bonjour! My name is David Issokson. I'm based in Victor, Idaho and have helped hundreds of students to learn French via Skype or Zoom since 2014. 
