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

Example Input: Sentence: 'two small white motor boats sitting still in a lake'. Count the occurrences of the word 'boats' in the given sentence.
Example Output: 1

Example Input: Sentence: 'a man dives to his right to make a forehand tennis shot'. Count the occurrences of the word 'to' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a vase and orange flower are sitting on top of a round small table'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
2