In this task, you need to count the number of nouns/verbs in the given sentence.

Example Input: Sentence: 'A polar bear stands on a rock surface in a zoo'. Count the number of verbs in this sentence.
Example Output: 1

Example Input: Sentence: 'People walking across an intersection in the city'. Count the number of nouns in this sentence.
Example Output: 3

Example Input: Sentence: 'A man bending down to pick up his skate board'. Count the number of verbs in this sentence.
Example Output:
2