「～ことができる」 is used to express ability or possibility. To use it, the verb must be in its dictionary form + ことができる.

In this case, 「使(つか)う」 (to use) becomes 「使(つか)うことができる」, meaning "can use".

This construction is used both for personal abilities and for rules or permissions, as in this case: "You can pay with a card."

Explanation of Incorrect Choices:

B. 「使(つか)った」 is the past form ("used"), but the sentence expresses possibility, not a completed action.

C. 「使(つか)って」 is the て-form, which is used to connect clauses, but it does not work with 「ことができる」.

D. 「使(つか)わない」 is the negative form ("do not use"), which changes the meaning completely.

「～たい」 is used with the ます-stem of a verb (removing ます).

「飲(の)む」 (to drink) → 飲(の)み + たい → 飲(の)みたい (want to drink).

「～たいです」 is a more polite way to express personal desires.

Explanation of Incorrect Choices:

A. 「飲(の)む」 is in dictionary form and does not express desire.

B. 「飲(の)ん」 is not a correct conjugation of 「飲(の)む」. This form does not exist on its own.

D. 「飲(の)ま」 is incorrect. It looks like a negative stem, but it cannot be used alone.

The grammar pattern ～たい is used to express the speaker’s or subject’s desire to do something, and it attaches to the stem form of a verb. In the sentence, it means "My younger sister wants to do her homework while listening to music." Here, したい comes from the verb する (to do), and turning it into したい shows that the sister wants to do her homework. The sentence combines that with 聞(き)きながら ("while listening to") to describe how she wants to do it. So overall, this is expressing a specific way she’d prefer to study—homework and tunes, multitasking style!

Explanation of Incorrect Choices:

B. 「する」 simply says she will do something.

C. 「した」 is in past tense, while ～ながら indicates simultaneous actions in the present.

D. 「しなかった」 is negative past ("did not do homework"), which contradicts the sentence.

「～てしまう」 has two main uses:

To express a completely finished action.

To express an unintended or unfortunate result.

Here, it is used for an undesirable outcome: losing an important document.

「置(お)いてしまった」 is the past tense of 「置(お)いてしまう」, meaning "I put it somewhere and now it's gone."

Explanation of Incorrect Choices:

B. しまう →  This is the dictionary form, but the sentence requires the past tense.

C. しまい →  Not a valid conjugation in this context.

D. しまって →  This is the て-form, which is used to connect sentences, but the sentence needs a final verb in past tense.

The grammar pattern のに is used to express contrast or unexpected results, similar to "even though" or "despite" in English. In the sentence, the speaker is saying: "Even though I studied Japanese for five years, reading the newspaper is still difficult." Here, のに connects two clauses that contrast with each other—the effort and time spent studying (which would normally lead to fluency), and the surprising or frustrating result that newspaper reading is still hard. The nuance is often one of disappointment or frustration, and it implies that the outcome is not what the speaker expected or hoped for.

Explanation of Incorrect Choices:

B. したので → This expresses a reason or cause ("because I studied"), but the sentence needs to contrast two ideas.

C. して → This is the て-form, which connects sentences, but it does not create contrast.

D. したから → Like ので, this explains a reason ("because I studied"), but it does not express contrast.