In English (USA) we use contributed when referring to some action which aids in completing or improving a task. Sometimes it is used when referring to fund raising, by helping to reach a monetary goal. ex "I contributed to the group research paper by writing the introduction." Attributed on the other hand is referring to something as the cause of some effect indicated. ex. "We attributed the bright lights in the distance, to the game going on at the stadium"

Hi, Meng! It's interesting that you mix up these two words, because I never think of them as being associated with each other! I suggest that you just think of CONTRIBUTE as a fancy way to say ADD. It is a pretty simple concept, I think. ATTRIBUTE is closely related in meaning to the concept of BLAME. Both words are used to name the CAUSE of an event or state of being. You use ATTRIBUTE when you want to GIVE CREDIT for something good or neutral, as opposed to placing BLAME for something bad. The sentence construction is different (and can be active or passive), but the meaning of ATTRIBUTE should be clear when you think of it as related to BLAME: I ATTRIBUTE my success TO you. I BLAME you FOR my failure. (Or I BLAME my failure ON you.) She ATTRIBUTES her good health TO her vegetarianism. She BLAMES meat FOR the poor health of her husband. (Or She BLAMES his poor health ON meat.)

''Contribute'' means ''to help a collective effort by giving something (like time or money) to it''. For example, if you give volunteer to help a charity, you ''CONTRIBUTE to the cause''. If you pay tax, you ''CONTRIBUTE to your country''. 'Normally, you ''attribute'' something to something else. ''Something else'' is the cause. ''The doctor ATTRIBUTED her illness to her soya allergy''. (The allergy is the cause of her illness) It can also mean ''to associate something (often art) with a particular person, group or thing For example, ''This style of writing can be ATTRIBUTED to the Victorians''. ''Attribute'' can also be a noun. It means ''quality'' or ''characteristic''. As you can see, ''to contribute'' is often active and ''to attribute'' is often passive. Not always though: ''This information WAS CONTRIBUTED by Simon''. (passive) ''You can ATTRIBUTE this to the fact that I can't sleep''. (active)