时量补语
Curiosity
In "I studied Chinese for three years," where does "three years" go? Putting it at the end like English is wrong.
Intuition
How long the action lasted (the duration) comes right after the verb, measuring the action's "length." With an object, the duration precedes the object (state the lasting first, the object after).
Visualization
Reorder the English-like [I][study][Chinese][three years] into Chinese [I][study-le][three years][Chinese]. The duration moves before the object.
Essence
Verb + le + duration + (de) + object (xue le san nian hanyu), or repeat the verb (xue hanyu xue le san nian). The duration precedes the object. If still ongoing, add another le at the end (yijing xue le san nian le, "have been studying for three years"). It marks length, not a point in time.
Examples
Mini-quiz
Which has the correct order for "I exercised for one hour"?