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

Q: Sentence: 'a big bear walks through some grass'. Find frequency of the letter 'a'

A: 4
****
Q: Sentence: 'a woman in a messy kitchen with a child'. Find frequency of the letter 'a'

A: 4
****
Q: Sentence: 'a man is straightening his tie in front of a mirror'. Find frequency of the letter 'n'

A:
5
****