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

Example Input: Sentence: 'a plate filled with various food items and a carton of milk'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'there is a man drinking whine from a glass'. Count the occurrences of the word 'a' in the given sentence.
Example Output: 2

Example Input: Sentence: 'a man rides a bike through the street in front of a motorcyclist'. Count the occurrences of the word 'a' in the given sentence.
Example Output:
3