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

Example Input: Sentence: 'a bear standing on top a piece of pipe with a chain attached'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a man wearing jeans and a tshirt with a cell phone on his belt'. Count the occurrences of the word 'belt' in the given sentence.
Example Output: 1

Example Input: Sentence: 'two people that are crossing the street that has some work being done'. Count the occurrences of the word 'that' in the given sentence.
Example Output:
2