YJ: Welcome to Chinese Studio. Wo shi Yajie.
Cam: Hello, everybody, Da4 jia1 hao3. Wo3 shi4 Cam. YJ, can you do me a favor?
YJ: Sure! What is it?
Cam: Well, you see, all my Chinese friends know I’m studying Chinese, so they often ask me the same question- ‘how long have you been studying Chinese’? But I don’t know how to answer that in Chinese!
YJ: well, you’ll figure it out in today’s Chinese Studio.

Key Words of the Day
How long have you been studying Chinese? 你学汉语多长时间了？多长时间 means ‘how long’. 学  to “study”, 已经, already. 才, only. All in today’s Chinese Studio.

YJ: How long have you been studying Chinese? 你学汉语多长时间了(ni3 xue2 han4 yu3 duo1 chang2 shi2 jian1 le)? ni3 means you. Xue2, second tone, means to study. And Han4 yu3 means Chinese language.
Cam: So xue2 han4 yu3 means to study Chinese.
YJ: Good. And多长 (duo1 chang2) means how long.
Cam: 多长 (duo1 chang2)
YJ: Right. duo1 chang2 is a general term that can be applied to either length or duration. Here we can say 多长时间(duo1 chang2 shi2 jian1), literally means how long time.  时间(shi2 jian1), time.
Cam: duo1 chang2 shi2 jian1, ‘how long’.
YJ: Correct. Put all phrases together, ni3 xue2 han4 yu3 duo1 chang2 shi2 jian1 le? How long have you been studying Chinese? Remember, the ending 了(le) is a particle word, meaning the completion of an action.
Cam: ni3 xue2 han4 yu3 duo1 chang2 shi2 jian1 le?

Conversation1:

Cam: Actually I’ve been studying Chinese for a year. I know a year is yi4 nian2. Can I give my answer by replacing ‘duo1 chang2 shi2 jian1’ with yi4 nian2? This would be ‘Wo3 xue2 han4 yu3 yi4 nian2 le’.
YJ: very good, Cam! But usually we’d like to put in some adverbs in front. For instance: 已经(yi3 jing1) means already. yi3, the third tone, and jing1, first tone.
Cam: yi3 jing1.
YJ: So Cam, if you want to say “I’ve been studying Chinese already for a year.”, you may say it in this way我学汉语已经一年了(Wo3 xue2 han4 yu3 yi3 jing1 yi4 nian2 le)。
Cam: Wo3 xue2 han4 yu3 yi3 jing1 yi4 nian2 le。

Conversation2:

YJ: and there is another adverb for you to choose from. It’s  才(cai2) ,second tone, means ‘only’. So when you want to say “I’ve been studying Chinese only for a year.” then you can say ‘Wo3 xue2 han4 yu3 cai2 yi4 nian2’.
Cam:  Wo3 xue2 han4 yu3 cai2 yi4 nian2’. But YJ, wher is the particle word ‘le’?
YJ: Good question. Actually here le can’t be used together with才(cai2) which means ‘only’. So it's Wo3 xue2 han4 yu3 cai2 yi4 nian2’. I’ve been studying Chinese only for a year.
Cam: Wo3 xue2 han4 yu3 cai2 yi4 nian2’.

Conversation3:

Cam: YJ, there is another question I often heard – how long have you been in Beijing? Can I use the sentence pattern we’ve just learned ?
YJ: Surely you can. You just need to replac xue2 han4 yu3 with lai2 bei3 jing1. ‘来北京(lai2 bei3 jing1)’ means to ‘be in Beijing’. 
YJ: So the question would be: 你来北京多长时间了(ni3 lai2 bei3 jing1 duo1 chang2 shi2 jian1 le)？How long have you been in Beijing?
Cam: ni3 lai2 bei3 jing1 duo1 chang2 shi2 jian1 le？

Conversation4:

Key Words Reminder
How long have you been studying Chinese? 你学汉语多长时间了？ 已经, already. 才, only.