Tonight I had dinner with one of my Japanese friends and he suggested I write about the difference between the words “can you”, “could you” and “would you”. So that is what I’m going to do.
In terms of formality, “can you” is the most casual, “could you” is more polite and “would you” is the most formal and polite. There is no major difference in meaning between “can you” and “could you” except that “could you” is more polite. However, there is a difference in nuance between “could you” and “would you”. The words “could you” focus on the ability to do something, but the words “would you” focus on the willingness to do something. For example:
Can you help me with my homework later? (said to a friend or family member)
Could you tell me how to get to the train station from here? (said to a stranger on the street)
Would you lend me your car this weekend? (said to a friend or family member, but in a very polite way because you want something from them)
Sometimes people get confused between the difference between “could you” and “would you” but there is one example sentence which usually helps people to understand. If a man is asking someone to marry him, he would say:
Would you marry me?
But he would NEVER say:
Could you marry me?
By saying, “Would you marry me?” he is asking “Are you willing to marry me?” but if he said “Could you marry me?” it sounds like “Do you have the ability to marry me?” (which sounds quite strange and VERY unromantic.) Here are some other examples for you to study:
Can you drive me to work today? My car isn’t working now.
Could you tell me how long I’ll have to wait until I can see the doctor?
Would you please stop tapping your foot? I’m trying to study.
So I hope this helps people to understand the difference between these words.
English Help Online's Blog 
K Said:
on July 5, 2010 at 11:20 am
Great explanation!
Ram Said:
on November 22, 2010 at 10:38 am
Good Explanation. Nice
Ram
http://www.firstcracker.blogspot.com
prc Said:
on December 29, 2010 at 2:26 pm
Good one. I liked it.
Thanks for sharing.
king Said:
on February 11, 2011 at 8:56 am
very nice. keep it up
i appreciate your efforts
Pvrk Said:
on January 7, 2012 at 2:03 pm
Thanks.
Qamar Said:
on January 11, 2012 at 2:30 pm
Thanks a lot for this clarification. Your style and way of teaching is great….keep it up, I believe lot of people out there need this type of blogs.
rufus Said:
on March 20, 2012 at 7:34 pm
Awesome narration with quite understandable examples
shikha Said:
on June 7, 2012 at 6:53 pm
very nicely explianed 🙂
helped a lot.
thank you 🙂
Ron Said:
on July 5, 2012 at 10:12 am
Very clear xplanation. Helps alot, thanks so muj
R Ahire Said:
on July 13, 2012 at 2:01 am
That was crystal clear!!
bubble Said:
on July 18, 2012 at 6:26 am
Now i understood the differences very clearly.Thanks a lot for your clear explanation.
Murali Vaishnavam Said:
on August 23, 2012 at 2:46 am
Awesome explanation… U are a good teacher… keep it up…
Stanley Said:
on August 29, 2012 at 7:04 pm
Well Explained..Nice examples
alok Said:
on September 10, 2012 at 12:07 pm
Nice explanation
Saiful Said:
on December 12, 2012 at 6:17 pm
Very clear on explanation and very easy to understand.
Saiful Said:
on December 12, 2012 at 6:18 pm
What is difference between “would you” & “will you”?
englishhelponline Said:
on December 13, 2012 at 1:22 am
Hi there.
I wrote a blog about that on August 9, 2010. Please check it out. I hope it answers your question.
Mike
Tafese Said:
on January 4, 2013 at 8:20 am
Nice,teaching program
vladimir Said:
on June 27, 2014 at 12:37 am
Thank you.
This is the best explanation….
ilia Said:
on September 2, 2014 at 4:47 am
I thank you as a teacher. Great explanation
Mohammad Said:
on September 25, 2014 at 12:48 pm
Hello and thank you very much for helpful explanation about how to use can could and would. I have had problems to use right ones of them