Count correct replies in quiz

I have a quiz.
German words are presented from a list.
The students must pick the corresponding English word.

The quiz goes through the wods on the list, starting at the first entry (index (0)) and stopping at the last entry (index -1) of the list.

This works so far.

At the same time, the script is supposed to count the number of correct replies of the student.
A correct reply is counted as a point.
(The variable is called “countpoints”.)
Each correct reply enhances “countpoints” by 1.
Each false reply subtracts one point from “countpoints”.
(The points are displayed through the command “say ‘countpoints’”.)

While all the words from the list
including their corresponding replies are presented properly,
the point count stops after the first correct reply has been counted (countpoints: “1”).
The following correct or false replies are no longer counted.

This means, while the questions in the loop are repeated,
the point count is not.

Can you maybe see the cause of the problem?
Thank you!