why does y some times substitute for e

Question

ya

Answer 1

In the Learn Spanish section, there is a whole lesson on this topic - 4.1 - which explains it very well.

Answer 2

No, but e can be substituted for y (the word "and") in certain circumstances.

Y becomes e when it precedes a word that begins with the i sound.

Y becomes e when it precedes most words that begin with i- or hi-

Y does not change before words, such as hierba, that begin with the y sound, regardless of spelling.

For example,

Reciben tratamiento cruel e inhumano. (They are receiving cruel and inhumane treatment.)