The correct expression is “fall for something hook, line, and sinker”. The word “fall” here means “to believe”. So when you fall for a story “hook, line, and sinker”, you believe the story completely, although it sounds pretty far fetched.
The expression means the same thing as “lock, stock, and barrel”. When you say that someone fell for something hook, line and sinker, you are passing a judgment on the individual. You are indirectly saying that he/she is pretty gullible; he/she is willing to believe anything somebody tells him/her. One can also say “swallow/buy something hook, line, and sinker”.
Here are a few examples. * Shyam expected his students to swallow his explanation hook, line, and sinker. * The children bought the story hook, line, and sinker.
Another common expression is, “fall hook, line, and sinker in love with someone/something”. * Everyone knew that Sarita had fallen hook, line and sinker in love with Ganesh. * As soon as Ramesh saw the car, he fell for it hook, line and sinker. * I’ve fallen hook, line, and sinker in love with Demi Moore.
Origin: This is an expression, which comes from the sport of fishing. I understand that sometimes a fish not only swallows the hook to which the bait is attached, but also some of the “line”. The sinker is the weight that is used to take the fishing line to the bottom. It is, however, very uncommon for a fish to swallow the “sinker”. So, if someone swallows your story hook, line and sinker, he/she believes your tall tale.
KYE 