Translation:The teacher does not see the student.
I get confused of where "nicht" is supposed to be placed.... e.g. why here is it at the end of the sentence?
The word ‘nicht’ appears at the end of the sentence because that's where the verb would have been had it not moved to the second position in the sentence. That's also the reason why ‘an’ is at the end of Fenix's example with ‘ansehen’.
I have previously written about the position of ‘nicht’ here:
It is important and important words tend to be at the end of the sentence in German. However, some words trump "nicht"'s end position: separable prefixes, predicatives, some adverbials
Ich sehe dich nicht. I do not see you.
Ich sehe nicht gut aus. I do not look good. (aus separable prefix, gut - predicative)
Ich sehe nicht mehr. I do not see anymore. (mehr adverbial?)
"to look at" has its own verb in German "ansehen". It is a verb with separable prefix, so it can be hard to recognize.
Der Lehrer sieht die Schülerin nicht an. The teacher does not look at the (female) student.
Der Lehrer sieht die Schülerin nicht. The teacher does not see the (female) student.
Der Leher will die Schülerin nicht ansehen. The teacher does not want to look at the (female) student.
Der Lehrer will die Schülerin nicht sehen. The teacher does not want to see the (female) student.
By the way: Der Schüler/die Schüler, the student/the students; die Schülerin/die Schülerinnen, the (female) student/the (female) students
No, it is accusative. You would need dative if the student becomes the indirect object.
Der Leher sieht die Schülerin nicht. (accusative) The teacher does not see the student.
Der Lehrer sieht der Schülerin nicht in die Augen. (dative) The teacher does not look the student in the eye.
I think Duolingo doesn't give us the necessary context to make us choose any particular option, unless there's a rule, or a common interpretation for german speakers for sentences like this. Anyway, if there's no rule or interpretation at all and we adjust to what Duolingo taught us till now, then there's no other way I can say "The teacher is not seeing the student" than "Der Lehrer sieht die Schülerin nicht.". If someone knows this is not necessarily true, please give us some answers!