Hello, I’m new on this website and I don’t know every function of LingQ. I’ve got simple question about known words. When I find a word which I don’t know I can add it to my LingQ list. Then I can practise it by flash cards. When I learned this word what am I supposed to do? When I click on “4 as known” the system add it to my known word bank but it remains on my lingQ list. When I click on “X” the word will be deleted from LingQ list but will not be added to my “known list”. How can I add words to my “known words” and delete from LingQ list? Probably It’s quite simple but I couldn’t find it out. I hope you will understand me. My english is not perfect yet but I’m still learning 
Once you create a LingQ it will always remain in your list of LingQs as a status 4 (known) word. The only way to remove it is by deleting it. However, since you very often need to refer to words you thought were known it is a good idea to keep it as a LingQ. You should really only delete misspelled words or foreign words or words you don’t want to learn right now.