Time Duration: 多久 (duōjiǔ) - How Long

In English, we move "how long" to the front. In Chinese, it usually stays after the verb. This feels weird at first. Just remember: action first, duration second. It is like saying "You wait how long?" This logic applies to most duration questions. It acts as a complement. It completes the meaning of the verb. You aren't just "waiting." You are "waiting for a specific length." If the action is finished, use 了. If it is still happening, use two 了. It sounds complicated, but it is quite logical. Think of it like a grammar traffic light. It tells you when to stop and measure.

1. 1There are three main ways to build this.
2. 2The Simple Version: Subject + Verb + 多久?
3. 3Example: 你要等多久？ (How long will you wait?)
4. 4The Completed Action: Subject + Verb + 了 + 多久?
5. 5Example: 你睡了多久？ (How long did you sleep?)
6. 6The Object Version (The Double Verb): Subject + Verb + Object + Verb + 了 + 多久?
7. 7Example: 你学汉语学了多久？ (How long have you studied Chinese?)
8. 8Yes, you repeat the verb. It feels repetitive. But it is the most natural way. You can also say: Subject + Verb + 了 + 多久 + Object.
9. 9Example: 你学了多久汉语？ (How long did you study Chinese?)
10. 10Both are correct. The first one is more common in speech.

Use it when the clock is ticking. Use it for travel times. "How long is the flight to Shanghai?" Use it for work experience. "How long have you worked here?" It is perfect for social situations. "How long have you known your best friend?" Use it when ordering food. "How long will the food take?" It is also great for hobbies. "How long do you practice guitar every day?" Basically, if you can measure it in minutes or years. 多久 is your go-to phrase. Even native speakers use it constantly. It is the bread and butter of conversation.

Do not use it for specific points in time. If you want to know "when," use 什么时候. 多久 is for length, not dates. Don't use it to ask for the time. That is 几点. Don't use it for distance. That is 多远. If you ask 你多久去北京？, it sounds wrong. You are asking "How long do you go to Beijing?" People will be confused. They might think you mean frequency. But usually, it just sounds like a mistake. Keep it strictly for duration. Don't let it wander into other categories.

Putting 多久 before the verb is the biggest trap. You might say 你多久等？ because of English. This is a classic "Chinglish" error. Always put it after the action. Another mistake is forgetting the object rule. If you have an object like "Chinese," you can't just stick 多久 anywhere. 你学多久汉语？ is okay but sounds a bit "stiff." Try to use the double verb or add a 的. 你学了多久的汉语？ sounds much smoother. Also, don't confuse it with 多久一次. That means "how often." One measures length, the other measures frequency. Don't mix your stopwatches with your calendars!

多久 and 多长时间 (duō cháng shíjiān) are twins. They mean the exact same thing. 多久 is shorter and more casual. 多长时间 is slightly more formal. You can use them interchangeably. Think of 多久 as the cool younger sibling. It is faster to say. Then there is 什么时候. This is the "when." 什么时候 looks for a date or time. 多久 looks for a number of hours or days. If the answer is "Monday," use 什么时候. If the answer is "Three days," use 多久. It is a simple divide. Don't cross the streams!