Answer :
In the provided sentences, the correct use of "can," "could," and "would" is as follows:
a. I didn't ___________ go to the party last night because I was sick.
In this sentence, the appropriate word to fill in the blank is "could." Therefore, the correct sentence is:
a. I couldn't go to the party last night because I was sick.
b. A: ___________ Ganesh cook Thakali food? B: Yes, he can.
In this sentence, the appropriate word to fill in the blank is "Could." Therefore, the correct sentence is:
b. A: Could Ganesh cook Thakali food? B: Yes, he can.