There's a difference between practicing saying stuff you already know, and actually targeting linguistic problems and tweaking your own Chinese to a higher level. The former can be accomplished in bars and at fruit stands. The latter requires what is commonly known in linguistic literature as an "informant" (see also Terry Marshall's The Whole World Guide to Language Learning for further reading on informants).Your informant should probably be a native speaker of Chinese who can answer your questions about Chinese. While I'm happy to make friends and chat with people, I have always been rather selective about who I think of as my informants.I'm going to skip the obvious tips about choosing an informant such as: you should like talking to her (or him), and her voice shouldn't make you want to run for earplugs. Here are some other things to keep in mind.

Default language

Your interaction with your informant will be one of the following:

• English default = her English is better than your Chinese. When communication breaks down, you both use English to clear things up.
• Chinese default = your Chinese is better than her English. When communication breaks down, you both use Chinese to clear things up.
• "Sparring partner" = your level of Chinese is the same as her level of English and both of those are low. You sort of hack your way through conversations and end up with communication by hook or by crook.

Each kind of interaction is valuable for different reasons. "Sparring partners" aren't really "informants" in the truest sense of the word. The goal for sparring partners just becomes communication and there is little chance to actually ask and get answers to linguistic questions.If your goal is really to improve your Chinese quickly, the best informants are English default informants (at least initially).

Informants can have various roles/skills

• Chat buddy = You and she chat for a while. If she hears a grammar mistake, she will usually tell you it's a mistake, and may be able to offer a better way of saying it. If the conversation is understandable, she usually ignores pronunciation and tone problems.
• Guide = When she hears a mistake, she can offer the correction even though she may not know why it's correct and your utterance wasn't. She points out pronunciation and tone problems when they arise and models the correct pronunciation for you.
• Linguist = She can explain grammatical rules, cite additional examples of a linguistic item, and offer suggestions not only on what pronunciation problems you have but also how to solve them.

English default linguist informants are the best. They are extremely rare and worth their weight in gold. They are usually people who have formal training in language pedagogy and/or linguistics.The reason I bring this up is it would be unreasonable of you to expect an informant who is a "Chat buddy" to be able to offer advice that only a "Linguist" would know. That doesn't make a "Chat buddy" less of an informant, but she may begin to feel like she is if you're always asking questions only a "Linguist" would know.

Mandarin (pǔtōnghuà 普通话)

When choosing an informant it's important to choose one that speaks "standard Mandarin" (biāozhǔn pǔtōnghuà 标准普通话) if possible. Here are 4 ways to find out about her Mandarin:

• Listen to her speak Chinese. If you know what standard Mandarin sounds like, then you should be able to recognize it. Coming soon: a post on common accents that are not standard Mandarin.
• Ask her where she's from. If a person is from northern China, she is more likely (though not guaranteed) to speak more standard Mandarin
• Ask her if she's taken the Mandarin test (pǔtōnghuà cèshì普通话测试). The levels are as follows:
  1. 1st Level (yī jí 一级)
     • A (jiǎ děng 甲等) = qualified for national broadcasting
     • B (yǐ děng 乙等) = qualified for provincial broadcasting
  2. 2nd Level (èr jí 二级)
     • A (jiǎ děng 甲等) = qualified to teach Chinese to foreigners or Chinese students
     • B (yǐ děng 乙等) = qualified to teach public school and university, or to hold city government positions
  3. 3rd Level (sān jí 三级)
     • A (jiǎ děng 甲等) = qualified to hold countryside government positions
     • B (yǐ děng 乙等) = not good
• Ask other people about her Mandarin. The Chinese all seem to know who speaks standard Mandarin and who doesn't. If you ask a friend or colleague of your prospective informant, "What do you think of her Mandarin?" they will usually readily tell you. Hesitation and anything less than an emphatic "Oh, very standard!" might be a red flag.

*Bonus*

• If she has the "Certificate for Teaching Chinese as a Foreign Language" ("duìwài hànyǔ jiàoshī zīgé zhèng" 对外汉语教师资格证) that's a real bonus. By the way, not that we really care, but the 3 grades for that certificate are high, medium, and low (gāo jí 高级, zhōng jí 中级, and dī jí 低级, respectively)

Compensation

The world's idea of reciprocity is alive and well in China. The reason the Chinese seem (or often really are) reluctant to accept gifts is they know everything has a price tag. If they take something from you, they know they owe you, and vice versa. So, if you've got an informant helping you with Chinese, they probably expect something in return. And personally, I wouldn't have it any other way.The types of compensation I've heard of in China are:

• English. "The first hour will be your asking me questions about English, and the second hour I can ask you any questions I have about Chinese."
• Money. "I'll pay you 10 yuan to record a 1 minute story and give me the pinyin transcript and English translation"
• Dōngxi 东西 (stuff). "I'll give you a bicycle if you ride it to my house once a week and let me practice Chinese with you."

In my experience, the English one is the most popular and also the most difficult to manage. Whatever the default language is usually ends up getting used WAY more than the agreed-on practice language. But who cares, right?

Homework

Unless the goal is just to chat in Chinese (that might be enough for some people) I've found it best to assign myself homework before the informant arrives, such as:

• Write a short story about myself. Then, I read the story to my informant and she listens to my pronunciation and grammar. I also provide the English translation if the compensation package includes English.
• Write a list of questions. Once, when I had just "hired" a new informant she asked, "But what do you want me to prepare for our first meeting." I said, "Don't you worry about that. I'll ask the questions. You just be Chinese. And believe me, you won't have time to answer even half of my questions." These questions can range anywhere from "Can I say ________?" which checks my grammar, to "What do you call your father's grandfather?"
• Write some Chinese I want the informant to record. I have a little microcassette recorder that I've used to record a native speaker saying little phrases. For example, "hǎo jiǔ bú jiàn 好久不见" ("long time no see"). Remember, gotta get those tones right.
• Write a list of vocabulary words I want to try to use. While I usually don't actually write this list, I do have in my mind some new words I want to be more fluent with. When the informant arrives I'll look for ways to use and incorporate them.

Oh look, the theme of homework is writing. It's the best way I know, and it guarantees that there will be some sort of concrete indicator of progress at the end of the session.Sure this is a lot to think about. But it doesn't have to be as formal as this sounds. These are just things to think about. Also you don't have to teach yourself Chinese like this. If you'd like someone else to structure your learning, perhaps enrolling in a local Chinese class would be best...