Discourse makers are rarely seen in learner work at the A1 level. Once the A2 level is achieved, learners are able to accurately use a few simple discourse markers.
As you know is found in the work of A2 level learners as a marker of shared knowledge. However, unlike native speakers, who exhibit a clear preference for placing this phrase in the middle of a statement, learners across CEFR levels use as you know most frequently to start a statement (despite being able to competently use the phrase in the middle of a sentence as well).
As you know, my parents are leaving home tomorrow night to go to Spain. (Cambridge English: Key; French)
As you know, I’m a good driver. (Cambridge English: Key; Turkish)
I can’t come to your wedding because, as you know, I live in England and on Thursday 18th July I’m going to take the FCE exam. (Skills for Life: Entry 2; Polish)
Learners at the A2 level are also able to use so as a discourse marker to summarise, usually in informal contexts.
So, what do you think? (Cambridge English: Key; Portuguese)
[talking about not being able to make it to a party] I have got an appointment with my dentist. So, I’m really sorry about that and I’m getting so sad. (Skills for Life: Entry 2; Farsi)
I’ll be free at 15.00. So, I’ll be at your house at 15.30. (Cambridge English: Key; Catalan)
Although the range of discourse markers used at the A2 level is quite limited, learners clearly demonstrate understanding of their functions. As learners progress to the B1 level, they make impressive progress in the range of discourse markers that they employ in their writing.