說人“半吊子”或是“半瓶醋”來形容一些人對某方面有一點知識，可是並不精通，英文有什麼對應的詞語?

我對某人看走了眼的“看走眼”英文怎樣說?謝謝

After Bill read one book on the history of Venezuela, he felt he was an authority on the subject, but he wound up looking like a fool in discussions with people who knew a lot more about it than he did. A little learning is a dangerous thing.

If you overestimate someone or something, you think that they are better, bigger, or more important than they really are.

他對寫程式只是個半吊子 = He only knows a little about programming.我對他看走了眼 = I was wrong about him.

事實上半吊子不就是初學者的意思?

Michael Wen 半吊子不是初學者,初學者應該是完全不懂才對.Anyway,thanks

對了,半吊子有相關英文的noun嗎?