Question

?teacher came in to my class. a/an​

Answer 1

Answer:

A teacher came into my class.

Answer 2

Answer:

A teacher came in to my class.

Explanation:

Since the word "teacher" is not a vowel, we must use "A"

"An" is usually used for words that start from a Vowel. The Vowels of our Alphabet are : A, E, I, O and U