What do you call a person who doesn't know the answer but says "I knew it" when I say the answer.
a person who doesn't want to do what I ask but says "I was going do it" when I finish the job. For example, Tim please take out the trash. In a minuate mom. He still doesn't do it so mom does it. When she finishes the job, Tim says" I was going to do it, mom"
It is hard a bit!
I think you can call it: CARELESS or something like that
Know-all…BrE informal someone who behaves as if they know everything. KNOW-IT-ALL. AmE
Longman Dictionary of Contemporary English, 1995
Know-all, know-alls. In informal British English, if you say that someone is a know-all, you are critical of them because they think that they know a lot more than other people. The American word is know-it-all.
Collins Cobuild English Dictionary, 1995
I'm not sure how Somerset Maugham used it. Perhaps he used it as the original poster described.