You are here: Home / Lessons / Therefore, hence, so, then, thus etc We use a number of expressions to show that what is said follows logically from what was said before. Keywords are: Therefore, as a result, so, then, consequently She was therefore unable to find a solution. So she had to quit her job. I think; therefore I am. ‘We have missed the train.’ ‘Then we are going to have to hire a taxi.’