Many people use flashcards to learn Chinese. Depending on what they're after, they use different cards. For example, if you want to get better at character recognition, you can use flashcards that have characters on the front and their meanings and/or readings on the back. You then look at the character and try to recall what the correct meaning/reading is.
If you want a more active way of studying, you should instead create a card that forces you to think how to express something in Chinese.
It could be through a cloze test (fill in the gap) where you have removed the word you want to learn and (optionally) left a clue, but otherwise just rely on context. You could also translate to Chinese from your native language or use pictures.
Why flashcards are better than just reading
Let's compare using flashcards to learn compared with just reading your textbook again or going over the list of words you want to remember. Flashcards are much better for several reasons:
Active recall instead of mere recognition – This is important. Research tells us that we remember things we process actively and that we make an effort to recall. Compare two scenarios: You see the character 我 and, right next to it, the translation "I; me", you review simply by looking at the two. You see the character 我 and then have to actively try to find its meaning in your long-term memory. Then, when you have given your answer, you check to verify that you are right. The first method is not very good; the second works much better. Make sure you actually practice remembering things, don't just look at them and hope they'll stick!
Flashcards are portable – You can of course carry your textbook with you, but it's a bit bulky and the likelihood that you pick it up and study while on the bus or while waiting for a delayed friend is minimal. However, if you have flashcards, printed or digital, they don't take that much space and you can bring them with you easily. Naturally, Lack of artificial context – When learning something in a list, such as in a textbook, it's easy to rely on artificial context. That means the placement on the page, the adjacent words and so on. A good example of this is numbers. You know how to say "eight", but only if you have said "seven" before that. You don't want to have to rely on this kind of artificial context. When you use flashcards, you will be called upon to remember how to say the numbers in any order. I say artificial context because some context is of course valuable, such as placing words in sentences.
Creating flashcards is good for you – Creating the flashcards themselves, digital or otherwise, is a good exercise in focused studying. You need to look up what the characters mean, you need to study stroke order and perhaps add an example sentence. If you just read what someone else has done (including flashcards made by other people), you might be tempted to just try to cram the words in without actually studying them properly first. Don't do that. Study they words carefully first. Don't review what you haven't learnt yet!
Digital or printed
If you've just started out learning or are learning in a casual manner, printed flashcards work well.
Digital flashcards have some advantages, though, such as being portable regardless of how many they are. Your phone doesn't become heavier, even if you add a million flashcards to Chinlingo. Digital flashcards are also easier to edit, update and backup. You can also search through them and find relevant information in seconds. Finally, a computer of some sort is needed to keep track of advanced scheduling and spaced repetition.
For some people, analogue flashcards just feel better though. If that's true for you, then by all means, don't go digital. You can reap many of the benefits of flashcards without using your phone or a computer!
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