When I used mon peur de hauteur , i was marked wrong. Also for on the top of .. I used au sommet., which was again marked wrong.

Hi Manpreet Kaur,

1. Peur is feminine and we just do not say - La peur des hauteurs

We say:

avoir le vertige /la  peur du vide 

2. Au sommet would be used more for a great height like a mountain or a hill.

En haut de is more suitable in this context.

But it’s best to accept these and just learn new expressions to build-up your vocabulary.

Bonne Continuation!