Subverted: Most of the time, when you think Frank is about to use the word "fuck", he says... something else.
But, in the statement after that, he uses the word "fuck" twice.
Alternatively, he cluster bombs his substitute swear.
A counter floats in the lower-left corner incrementing with every "fuck". And it frequently spins so quickly as to be unreadable.
Every other word out of Frank's mouth is some variation of the word. Literally.
Frank says "Fuck" very very often unless he's enraged which makes him shout "Gosh Dang It to Heck!" instead.
Alice: "I wish I had a dollar for every time Frank cusses..". Genie: "Your wish is my command!" Fast forward after the movie, in the "Where Are They Now?" Epilogue, we see Alice in a huge mansion getting more money by the second.
Zig Zagged: Just as Frank is going to use the word "fuck", he says "frick". But on occasions he overly uses the word "fuck". Then it is discovered that he was taught that "frick" is the real F bomb and that "fuck" is just another less-extensive way of saying the real F bomb, "frick". However, it is shown that he thinks that the F bomb, in general, is not obscene language, but rather a special word reserved for things you truly care about and idolize, like the word "love".