It has nothing to do with English.
It only depends on whether the character just before 이에요/예요 has a consonant at the bottom (called 받침).
For example, "받" has ㄷ and "침" has ㅁ as 받침, but none of the three characters in 이에요 has 받침.
이에요 is after a word ending with 받침 (only the last syllable of the word counts).
Ex) 이것은 책이에요. 좋은 날이에요. 저는 학생이에요. (책, 날, 생)
예요 attaches to a word ending without 받침.
Ex) 이 곳은 학교예요. 여기예요, 여기. 아주 좋은 날씨예요. (교, 기, 씨)