Can vs. Could – English Grammar Exercises for A2
Your phone battery is dead, and you are texting your roommate to borrow a charger and a few other things. Read the text messages carefully and choose the best option (A, B, C, or D) to complete each sentence.
1 “Hey roomie! My phone is at 1%. ______ I borrow your charger for an hour?”
(A) Could
(B) Can
(C) Do I can
(D) Can I to
2 “I left my charger at the library yesterday, and I ______ go back to get it because it was raining heavily.”
(A) can’t
(B) couldn’t
(C) didn’t can
(D) don’t can
3 “Roommate: Sure, no problem! It is on my desk. You ______ take it.”
(A) can
(B) could
(C) can to
(D) cans
4 “Thanks! Also, ______ I use your laptop to send a quick email to my professor?”
(A) Do I can
(B) Could I to
(C) Can
(D) Am I can
5 “Roommate: I would let you, but I ______ remember my password right now! I am completely locked out.”
(A) can’t
(B) couldn’t
(C) not can
(D) don’t can
6 “That’s okay. ______ you tell me where the TV remote is?”
(A) Do you can
(B) Can
(C) Could you to
(D) Are you can
7 “Roommate: I looked everywhere for it this morning, but I ______ find it.”
(A) can’t
(B) couldn’t
(C) didn’t can
(D) wasn’t can
8 “Oh, I just found it under the sofa! By the way, ______ I eat this last slice of pizza in the fridge?”
(A) Could
(B) Can
(C) Do I can
(D) Must I to
9 “Roommate: Actually, you ______ eat that. I am saving it for my lunch tomorrow.”
(A) couldn’t
(B) don’t can
(C) can’t
(D) not can
10 “Oops, sorry! ______ I make some of your pasta instead?”
(A) Can
(B) Could
(C) Can I to
(D) Am I can
11 “Roommate: Yes, of course. You ______ use any of the dry food in the cupboard.”
(A) cans
(B) could to
(C) can
(D) can to
12 “Roommate: Hey, I am going to a party tonight. ______ I wear your black leather jacket?”
(A) Could
(B) Can
(C) Do I can
(D) Can I to
13 “You ______ wear it, but please don’t spill any drinks on it! I just washed it.”
(A) can
(B) could
(C) can to
(D) cans
14 “Roommate: I promise I will be careful. Last time I borrowed it, I ______ even eat because I was so worried about making it dirty!”
(A) can’t
(B) couldn’t
(C) didn’t can
(D) wasn’t could
15 “Haha, relax! You ______ wash it in the washing machine if it gets a little dirty anyway.”
(A) can
(B) could to
(C) can to
(D) cans
16 “Roommate: I forgot my keys inside the apartment. ______ you open the front door for me?”
(A) Do you can
(B) Could you to
(C) Can
(D) Are you can
17 “I am at the supermarket right now, so I ______ open the door. You will have to wait for 15 minutes.”
(A) couldn’t
(B) can’t
(C) don’t can
(D) didn’t can
18 “Roommate: Oh no! I ______ call the landlord to let me in because my phone has no credit.”
(A) can’t
(B) couldn’t
(C) wasn’t can
(D) not can
19 “Don’t worry, I ______ text him for you right now on my way home.”
(A) can
(B) could
(C) can to
(D) cans
20 “Roommate: You are a lifesaver! ______ I buy you a coffee tomorrow to say thanks?”
(A) Can
(B) Could
(C) Can I to
(D) Am I can
ANSWER KEY & EXPLANATIONS
1 Key: (B) Can
Explanation: – Why it’s correct: When asking for permission from a close friend or roommate, “Can I…?” is the most natural choice. It is friendly and informal.
- Why others are wrong: (A) “Could I” is grammatically correct, but it is used for formal and highly polite requests. Using “Could” with a roommate sounds too distant and unnatural (khách sáo). (C) and (D) are grammatically invalid.
2 Key: (B) couldn’t
Explanation: – Why it’s correct: “Yesterday” indicates a past event. The inability to go back happened in the past, so we use “couldn’t”.
- Why others are wrong: (A) is present tense. (C) and (D) incorrectly use “do/did” with a modal verb.
3 Key: (A) can
Explanation: – Why it’s correct: The roommate is giving permission in the present (“You can take it”).
- Why others are wrong: (B) “Could” is not used to give permission. (C) adds an illegal “to”. (D) adds an illegal “-s”.
4 Key: (C) Can
Explanation: – Why it’s correct: An informal request to a roommate.
- Why others are wrong: (A) and (D) use invalid auxiliaries (“Do”, “Am”). (B) adds “to”.
5 Key: (A) can’t
Explanation: – Why it’s correct: “Right now” indicates a present inability to remember the password.
- Why others are wrong: (B) is for the past. (C) is the wrong word order (must be cannot/can’t). (D) uses “don’t”.
6 Key: (B) Can
Explanation: – Why it’s correct: A friendly, informal request for a favor.
- Why others are wrong: (A) “Do you can” is invalid. (C) “Could you to” has an illegal “to”. (D) uses “Are”.
7 Key: (B) couldn’t
Explanation: – Why it’s correct: “This morning” places the action of searching and failing in the past. We use “couldn’t” for past inability.
- Why others are wrong: (A) is present tense. (C) and (D) use invalid auxiliary verbs.
8 Key: (B) Can
Explanation: – Why it’s correct: Asking for informal permission to eat the pizza.
- Why others are wrong: (A) “Could” is too formal and overly polite for a roommate. (C) and (D) are grammatically invalid.
9 Key: (C) can’t
Explanation: – Why it’s correct: The roommate is denying permission in the present (“You can’t eat that”).
- Why others are wrong: (A) is past tense. (B) and (D) are structurally invalid.
10 Key: (A) Can
Explanation: – Why it’s correct: An informal request for an alternative option.
- Why others are wrong: (B) “Could” is too formal. (C) and (D) are invalid.
11 Key: (C) can
Explanation: – Why it’s correct: Granting permission in the present.
- Why others are wrong: (A) Modals never take an “-s”. (B) and (D) Modals never take “to”.
12 Key: (B) Can
Explanation: – Why it’s correct: A casual request to borrow clothes. “Can I wear…” builds closeness.
- Why others are wrong: (A) “Could” creates unnecessary distance between close friends. (C) and (D) are invalid.
13 Key: (A) can
Explanation: – Why it’s correct: Granting permission in the present.
- Why others are wrong: (B) “Could” is not used to grant permission. (C) and (D) are invalid.
14 Key: (B) couldn’t
Explanation: – Why it’s correct: “Last time” places the situation in the past. The speaker had a past inability to eat due to worry.
- Why others are wrong: (A) is present tense. (C) and (D) are invalid.
15 Key: (A) can
Explanation: – Why it’s correct: Stating a present possibility/ability (it is possible to wash it).
- Why others are wrong: (B) and (C) have an illegal “to”. (D) has an illegal “-s”.
16 Key: (C) Can
Explanation: – Why it’s correct: An informal request for help (“Can you open the door?”).
- Why others are wrong: (A), (B), and (D) all have major grammatical errors (“Do”, “to”, “Are”).
17 Key: (B) can’t
Explanation: – Why it’s correct: “Right now” indicates a present inability to open the door because the speaker is at the supermarket.
- Why others are wrong: (A) is past tense. (C) and (D) use “don’t/didn’t”.
18 Key: (A) can’t
Explanation: – Why it’s correct: A present inability due to a lack of phone credit.
- Why others are wrong: (B) is past tense. (C) and (D) are invalid.
19 Key: (A) can
Explanation: – Why it’s correct: Offering to do something right now.
- Why others are wrong: (B) “Could” makes the offer sound uncertain. (C) and (D) are invalid.
20 Key: (A) Can
Explanation: – Why it’s correct: Offering a friendly favor/asking permission to treat the roommate (“Can I buy you a coffee?”).
- Why others are wrong: (B) “Could” is too formal. (C) and (D) are invalid.
GRAMMAR POINTS TO REMEMBER
- Asking for Permission (Can vs. Could):
- Can I…? is used for Informal Permission. It is the perfect choice for family, close friends, and roommates. It shows that your relationship is close and comfortable.
- Example: “Hey, can I borrow your charger?”
- Could I…? is used for Formal Permission. It is highly polite. You use it with your boss, your teacher, or a stranger. If you use “Could” with a best friend, it sounds weirdly distant or too formal (khách sáo).
- Example: “Excuse me, Mr. Smith, could I borrow your pen?”
- Giving and Refusing Permission:
- When someone asks for permission, we reply with can or can’t. We do not reply with “could”.
- Right: “Yes, you can.” / “No, you can’t.”
- Wrong: “Yes, you could.”
- Past vs. Present Inability:
- Use can’t for things you are unable to do right now. (e.g., I can’t find my keys today.)
- Use couldn’t for things you were unable to do in the past. (e.g., I couldn’t find my keys yesterday.)
- The Grammar Rules:
- Never use do/does/did with Can or Could. (Say: Can you?, NOT Do you can?)
- Never put to after Can or Could. (Say: I can go, NOT I can to go).