Learners of Russian: do you recollect the funniest mistake you've made in Russian? I remeber myself saying, while describing (in the class) autumn in Russia:

В сентябре начинаются половые работы...

Naturally, I meant полeвые работы but at first I didn't notice the mistake. It was only after the teacher (a young WOMAN) & some of my friends burst out laughing, did I get but quickly