Why vs. because

[Christina328]

English Language Tests, Intermediate level

ESL/EFL Test #99 "Student Teacher Dialogue (2)", question 8

Student: Another problem is I don't understand ......... there are two words sounding the same — T and one O and T double O.

(a) because
(b) whenever
(c) why
(d) that's why

English Language Tests, Intermediate level

ESL/EFL Test #99 "Student Teacher Dialogue (2)", answer 8

Student: Another problem is I don't understand why there are two words sounding the same — T and one O and T double O.

Correct answer: (c) why

Your answer was: incorrect
Student: Another problem is I don't understand because there are two words sounding the same — T and one O and T double O.
_________________________

Dear Sir

why should I choose "why" here

thanks a lot in advance

Stone

[Conchita]

I don't understand why... means: I don't understand for what reason... and refers to the thing you don't understand.

I don't understand, because... means: The reason I don't understand is that... and refers to why you don't understand something.

I hope I haven't managed to confuse you more!