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

Example Input: Sentence: 'An elephant is by itself standing for the picture'. Count the number of verbs in this sentence.
Example Output: 1

Example Input: Sentence: 'a young teen boy doing a trick on his skateboard'. Count the number of verbs in this sentence.
Example Output: 1

Example Input: Sentence: 'A man sits in a cart pulled by a horse'. Count the number of verbs in this sentence.
Example Output:
2