In this task, you need to count the occurrences of the given word in the given sentence.

Sentence: 'a big rig is driving through a construction site'. Count the occurrences of the word 'big' in the given sentence.
1

Sentence: 'a young boy in traditional clothing holding a fan and a cell phone'. Count the occurrences of the word 'boy' in the given sentence.
1

Sentence: 'a person crossing a wet street with a pretty umbrella'. Count the occurrences of the word 'a' in the given sentence.

3