débutant

[edgy viper]

Please be patient

Our volunteers look into many questions every day; sometimes it takes them a little while to answer.

Pro tip: you can rename the thread title with `.tr <thread name>`

Make it descriptive, including relevant context, but also to the point. This way you improve your chances of getting a more relevant and specific answer.

[fair grotto]

For starters, « que » as a conjunction can NEVER be dropped so where we can say, 'I know that you're right / I know you're right', with either version being correct, in French we can only say « Je sais que tu as raison ».
So, I think that your song lyric uses « tu sais » not as its own clause – because otherwise that « que » wouldn't be dropped – but as an exclamation and so what's dropped here is the comma.
« Mais tu sais**,** je pleure quand tu me souris (But you know**,** I cry when you smile at me) »

When I looked up the lyrics and found the song, there were some sites that omitted the comma and some who didn't like Musixmatch: « Mais tu sais, je pleure quand tu me souris ». Apple Music instead separates them into separate lines: