J'irai si tu y vas.

English Translation

I’ll go if you go.

Can someone explain why there is the “y” in tu y vas?

It’s like saying, “I’ll go if you go there”.

The pronoun y usually means ‘there’ and the same position rules apply as for direct object pronouns. For example:

  • Elle est à la banque . Elle y est pour changer de l’argent. – She is at the bank. She is there to change money.

You can read more here.


Your question is possibly, as well, why y before vas only, and not before irai.

It is simply standard practice to avoid the hiatus between the two i sounds in that expression.

A linguistic mutilation to please the ears called haplology (not unique to the French language).