Question

Mark prevailed "upon" me to join him for the picnic
Why we used here preposition UPON
Please EXPLAIN

Answer 1

Prevail means to successfully persuade someone of something. If you were a Presidential adviser and you convinced him to make a National Day of Pet Appreciation, then you prevailed upon him to recognize pets. Prevail can be used for different kinds of success. If you prevail upon someone, you have influence on them.

Answer 2

Because Mark coaxed me.