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

Example Input: Sentence: 'People are boarding and departing a train at a station'. Count the number of verbs in this sentence.
Example Output: 2

Example Input: Sentence: 'A black and white image of a park bench'. Count the number of verbs in this sentence.
Example Output: 0

Example Input: Sentence: 'Two people relax at the beach while a man surfs'. Count the number of verbs in this sentence.
Example Output:
2