I entered "Der Lehrer." The answer is obviously supposed to be Die Lehrer because it is plural. However, the program tells me that I should use "die" to represent feminine nouns in the nominative case like Lehrer. Lehrer is a masculine noun though.
The 'Tips and Notes' (blue button left of the Hearts) of this lesson have a good chart of how the gender and plurality change the article.
I am confussed. In the previous example, it had Der Lehrer and when I put "The teacher" it told me I was wrong and said it was "The teachers". Here it ask for the german of "The teachers" which I replied as "Der Lehrer" and it told me it was wrong and said the correct one is "Die Lehrer". What is the difference between the two to cause this change?
Die Lehrer, means male teachers. How do you a group a teachers in german? both Male and female persons mixed.
As in many other languages, in that case generally the male plural is used. So "die Lehrer" also works, if any women are part of the group and "die Lehrerinnen" would only be used if the group is exclusively female.