En means 'of them', 'of it' or 'some'
En means 'of them', 'of it' or 'some'. It replaces words about quantity and words with de.
It comes before all parts of the verb. For example:
I ate some cake → I ate some
- j'ai deux enfants → j'en ai deux - I have two children → I have two of them
- elle a bu du café → elle en a bu - she drank coffee → she drank some
- ils ont beaucoup d'argent → ils en ont beaucoup - they have a lot of money → they have a lot of it
Y means 'there'. It replaces words with à + a place and en + a place, for example:
I went to town with my friend → I went there with my friend
It comes before all parts of the verb:
je suis allée à la piscine → j'y suis allée - I went to the swimming pool → I went there
elle va en France l'été prochain → elle y va l'été prochain - she's going to France next summer → she's going there next summer