Confusing English Words – can / could / able to

بسیاری از کلمات وجود دارند که معنی یکسانی دارند، اما در واقع تعاریف و کاربردهای مختلفی دارند.
شما می خواهید درست صحبت کنید و از به کار بردن کلمات نادرست خودداری کنید، اما در مورد معنی دقیق و کاربرد هر کلمه کاملا مطمئن نیستید.
بعضی از زبان آموزان حتی به دلیل تردیدهایشان از به کار بردن کلمات خودداری می کنند!
هدف ما در این سری از پست ها روشن کردن رایج ترین کلمات گیج کننده در انگلیسی است.

can / could / able to

:Can and able to are the same in the present tense

?Can you take on this project
.Yes, I can take on this project

?Are you able to take on this project
.Yes, I‘m able to take on this project

:The negative forms are can’t and not able to – or unable to

.Sorry, I can’t take on this project
.Unfortunately, I’m not able to take on this project
.Unfortunately, I’m unable to take on this project

.Can/can’t are more informal and more common in everyday speaking. Able to and not able to / unable to are a little more formal

:In the past, we use could/couldn’t or was/wasn’t able to (or was unable to)

:In general, both are used in the negative form

.I wasn’t able to finish all my homework yesterday
.I was unable to finish all my homework yesterday
.I couldn’t finish all my homework yesterday

:”But in the positive form, “was able to” is a little more common than “could

.I was able to leave work a little early yesterday

!In the future, there is only will/won’t be able to. Don’t say “will can” or “won’t can” – it’s a common error in English

.I have some free time tomorrow, so I‘ll be able to work on this project
.Sorry, I won’t be able to go fishing tomorrow. I have another commitment

:When you are making a polite request for someone to do something, use “could” (more formal) or “can” (more informal)

?Could you please bring me a glass of water
?Can you please bring me a glass of water

:When asking about someone’s abilities, you can use either CAN or ABLE TO

?Can you read Japanese
?Are you able to read Japanese

.Can is probably more common in spoken English, simply because it’s shorter