Taking a test for fun to improve my English. English is my third language and it is very hard. I have been googling and getting more confused. I ran across this sentence "One time, I asked my mom how come my little sister doesn't feed them."
Link to the whole quiz at http://www.englishforeveryone.org/PDFs/To_Be_Exercise_4.pdf
I was wondering. Why is "feed" in present tense and "asked" is in past tense? How do i find out more about this kind of sentence structure.
Should it be "I asked my mom how come my little sister doesnt fed them" or "I asked my mom how come my little sister didnt feed them" or "I asked my mom how come my little sister didnt fed them"
Thanks.
Edit2:
I was doing a fill in the blanks quiz. Below is half of the quiz.
Next, I feed the pigs. One time, I asked my mom how come my little sister doesn’t feed them. She said it is because my sister (be, not) ____ ____(8) strong enough. But I still don’t understand. She is almost as strong as me! I guess my mom doesn’t want my sister to get hurt. After all, the pigs can (be) ________(9) pretty rough, especially when they (be) ________(10) hungry.
edit3: This is how I feel right now after reading all the responses.
https://www.youtube.com/watch?v=fk-Gn3w2gt0
Everything is not so straightforward.
Thank everybody who contributed. When I wake up tomorrow, I will work more on it.