verb 'sein' - to be practice conjugating the verb 'sein'. singular plural ich bin - I am wir sind-we are du bist - you are ihr seid-you are er,sie,es ist - he,she,it is sie sind-they are Sie sind-you are (polite form) Tools See a list of terms used in these activities. Matching Flashcards (Java / non-Java) Concentration Word Search This activity was created by a Quia Web subscriber. To learn how to make your own, just like this, click here.