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

Sentence: 'a family sitting at a table in a restaurant looking at their phones'. Find frequency of the letter 't'
8

Sentence: 'some sheep are standing in a grassy field'. Find frequency of the letter 'n'
3

Sentence: 'the couch has a cover over it in the living room'. Find frequency of the letter 'n'

2