Hi Paul, To answer your questions about whether there is a difference between "before I speak” and “before speaking”, I would say there is no difference in meaning. In terms of grammar "before I speak" is an adverbial clause, and "before speaking" would be a reduced adverbial clause (more like a phrase now). It is just simplified and therefore a good way to vary your sentences so that they don't become too repetative. I hope that helps.

'Before I am speaking' is incorrect. But your other examples are grammatically correct.

Hi Keith, Thanks for your explanation. Am I right when I say “I have to translate what I want to say in my head when speaking.”? According to what I learned from your answer I cannot use “ when I speak” here.

when I speak = 'immediately after I speak/say something' eg: when I speak to him, he speaks to me. (first me, then him) when speaking = during the time that I'm speaking. :)

Thank you, Mohammed. Could you tell me whether there is a difference in meaning (“when I speak” vs “when speaking”), please?