Hi

All fruit trees drop fruit, apples and pears do the same this time of year , the tree just keeps what it can manage to grow properly , nothing to worry about.

How old is the tree ?

Gg

Hi
Thanks - tree is 4 yrs old

Do they all fall off, or just some of them?

Last year they all fell off, although there wasn't many. This year there's loads but they are beginning to fall again.

A few falling isn't much to worry about - high winds can knock some off, but if you lose the lot, inspect the tree thoroughly for any signs of infestation or infection. Otherwise, sudden frost on the fruitlets can cause this, dryness at the roots or, conversely, sitting in soil that's too wet. As the fruitlets ripen, birds can attack them and you lose some that way.