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

Sentence: 'a man with glasses a collar shirt and a tie on'. Count the occurrences of the word 'a' in the given sentence.
3

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

Sentence: 'a cow scratches her head with a back leg'. Count the occurrences of the word 'leg' in the given sentence.

1