SIMPLE GERMAN PRESENT TENSE Edit
In English, the present tense can be simple or progressive (as in "I eat" or "I am eating"). Both forms translate to just one German present tense form, because there is no continuous tense in standard German. So, "she learns" and "she is learning" are both "sie lernt."
WIE GEHT'S? Edit
There are many ways to ask someone how he or she is doing. Take "How are you?," "How do you do?" and "How is it going?" as examples. In German, the common phrase or idiom uses the verb "gehen" (go): "Wie geht es dir?" (How are you?).
WILLKOMMEN CAN BE A FALSE FRIEND Edit
In German, "Willkommen" means welcome as in "Welcome to our home", but it does not mean welcome as in "Thank you - You're welcome". The German for the latter is "Gern geschehen" or "Keine Ursache".
Duo is the name of Duolingo's mascot (the green owl).