What's the different between this words?
When we can use one in a sentence and when we can use the other one...?
Thank you very much.
Helpful for people, useful for objects is a rough rule.
My friend is always very helpful.
When on holiday, a phrase book is useful.
Ruben, the distinction between "helpful" and "useful" is a very fine, or narrow distinction.
USE refers to the Utility of a thing. It does a job. Tools are used to do a job. They are adequate, but not more than merely adequate. Things which serve a "use" are satisfactory.
An answer to a question can be "useful" but not necessarily "helpful". I can give an answer that is merely useful, but not really "helpful".
For example, you can ask a question about which Accent is best regarding the study of English.
You might ask if you should study a British or American accent.
My "useful" answer to you would be like this: "It does not really matter. Study both".
My "helpful" answer would offer more information. I could tell you for example, that many foreign students of English operate with a massive misundertanding about the study of English, because they
are convinced that Accent matters; but I could explain to you that in the United States, nobody cares about an accent. Accents are everywhere in America.
Another example: You could ask if the Rules of Grammar are the most important knowledge for you to know to become a confident speaker of English.
My "useful" answer would be to write; "No.".
My "helpful" answer would tell you that repetitious pronunciation exercises which you recite aloud every day will make you a more effective speaker than will the knowledge of English Grammar.
Thanks for your examples Bruce!
Thank you very much!
Now, I understand it.