Check for repetition and check for first 100 words and check for first sentence

Hi I need 2 formulas,

QUESTION 1 - check for repetition:
I need to crawl from sheet 2 colomn A1 into sheet 1 B2->B8 and count how many times the keyword has been repeated in sheet 2 colomn A1


QUESTION 2 - Check first 100 words:
I need to crawl from sheet 4 colomn A1 into sheet 3 B2->B5 and count how many times the keyword has been repeated in sheet 4 colomn A1 (but only for the first 100 words)


QUESTION 3 - Check first sentence :
I need to crawl from sheet 6 colomn A1 into sheet 5 B2->B5 and count how many times the keyword has been repeated in sheet 6 colomn A1 (but only for the first sentence)


Please check attachment

THANK YOU