"Corinna teaches students."
Translation:Corinna discipulas docet.
'Discipuli' is masculine nominative plural. Here you need the accusative, since 'the students' are a direct object (i.e., the students are taught). Since 'students' has no gramatical gender in English, both 'discipulos' (masculine) and 'discipulas' (femenine) are right, since they are accusative plural. For more declensions of 'discipulus', please check: http://latindictionary.wikidot.com/noun:discipulus
I've been feeling really good about my understanding of Latin up until this segment. Now - while I have a handle on the base words - I am getting constantly flummoxed by word endings. I'm getting quite frustrated, as this section of the course feels a lot like being thrown into the deep end. Can anyone recommend any sources for understanding why certain words end differently? I'm talking real basics here, since Duolingo is my first experience of trying to learn Latin.
https://www.youtube.com/playlist?list=PLI76N29qybf8a9pkSzD9X0PX3a3PgO2_- This^ is an intoductory Latin course that starts with the relevant grammar in English and then explains the Latin basics quite well.
latindictionary.wikidot.com This^ is a very helfpul website full of charts for declensions and conjugations. Just search an english or latin word in the index and click on it.
Because "doceo" has a double accusative regime. In Spanish (it is my native language) these accusative are called "acusativo de cosa" (accusative of matter or thing I suppose) and "acusativo de persona" (accusative of person). In this case "discipulas" or "discipulos" is the "acusativo de persona" and the matter or thing is not specified.