Learn French: Je suis derrière toi !

In French, when a pronoun comes immediately after a preposition (like the location word derrière), you must use a 'stressed pronoun.' For 'you' (informal), that word is toi, not the subject pronoun tu.

How does this fit into our lesson about où (where)?

This sentence is the perfect answer to a 'where' question! If someone asks Où es-tu ? or Tu es où ? (Where are you?), you use a location word like derrière to tell them exactly where you are.

Doesn't the word derrière mean 'bottom' or 'butt'?

Yes, it does! Just like in English, the noun un derrière can refer to a person's bottom. But its main job in French is being a preposition that means 'behind,' which is exactly how it is being used here.

Could I use derrière to say I am 'behind schedule'?

No, derrière is strictly used for physical locations in space. If you want to say you are behind schedule or running late, you would use the phrase en retard (for example, Je suis en retard).