一、If you don't understand 如果你听不懂 "Sorry, I don't understand." 抱歉,我听不懂。 "Sorry, could you repeat that?" 抱歉,你能再说一遍么? "Sorry? I didn't get that." 什么?我没听懂。
二、If you don't know the word 如果你不知道那个单词 "I can't find the word I'm looking for…" 我找不到那个我想说的词... "I'm not sure that this is the right word, but…" 我不确定这是不是一个合适的词,但是... "What I want to say is…" 我想说的是...