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

Example Input: Sentence: 'young teenage boy on his skateboard on the street with people on the curb'. Count the occurrences of the word 'on' in the given sentence.
Example Output: 3

Example Input: Sentence: 'a group of people standing outside in a park eating food on paper plates'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a floating watch tower along a tower on dry land with the tide out'. Count the occurrences of the word 'tower' in the given sentence.
Example Output:
2