In this task, you need to count the number of times the given letter appears in the given sentence.

Sentence: 'three young children playing with a ball in front of a huge bridge'. Find frequency of the letter 'e'
5

Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'
3

Sentence: 'a no parking sign outside of a brown building'. Find frequency of the letter 'e'

1