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

Example Input: Sentence: 'a little kid skiing down a hill holding ski poles'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man with a tennis racket in front of spectators'. Count the occurrences of the word 'tennis' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a man sitting at a table with a plate full of food and drinks'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3