The Review System

MandarinBanana uses a review system which aims to improve upon the traditional way of reviewing every individual Chinese character: instead of reviewing characters in isolation the focus is on reviewing characters in sentences. Additionaly, the internal structure of Chinese characters is taken into account when deciding which review should be next. Let's have a look at the state of the art before I explain how the review system works in detail.


Learning Chinese characters is hard. The advent of spaced repetition software (SRS) was a big leap forward in the right direction and made learning thousands of Chinese characters in a reasonable amount of time possible. "Possible" means that even with SRS it still takes hundreds of hours to learn Chinese characters. Let's discuss why that is and how to improve the system.

The problem with spaced repetition of individual characters

Even with spaced repetition software and mnemonic systems, learning Chinese characters to native-like levels is still extremely hard - simply due to the high number of thousands of Chinese characters to learn. Let's say you want to remember a few thousand Chinese characters, and you get every review in the spaced repetition software right. In that case every character generates a review after one minute, 10 minutes, one day, a few days, and so on.

  • Even if you get every review right, you have to complete tens of thousands of reviews to learn a few thousand characters.

On top of that, take into account that you do not get every review right on the first try. Although doable over the course of a few years, completing tens of thousands of reviews is definitely a huge grind.

The problem is that there's a separate, isolated review scheduled for every individual Chinese character. Our goal should be to not review every character individually, but to review many characters at once. In addition, we should take into account that Chinese characters are (in most cases) constructed by combining other Chinese characters.

Reading practice

Let's change perspective for a moment and look at an extremely simple, yet extremely effective way of learning: reading sentences.

  • Reading sentences is terribly effective because each time you read a sentence, you're reviewing ten to twenty characters at the same time.

Let's assume you have a text in front of you tailored exactly at your own level, where you can comfortably read a few characters per second. In just a few minutes of reading you'll have reviewed hundreds of Chinese characters! This feat alone show the power of reading texts for reviewing Chinese characters.

Of course, it's not that simple in reality. You basically never have a text available tailored exactly to your current level; it's hard to track your progress; the appearance of Chinese characters is governed by the character frequency, not by what characters you should review next; you have to actively look up words you don't understand; the list goes on.

The key message here is that nevertheless we should use sentences to review Chinese characters simply because it's so much faster to review characters in parallel.

There are two more equally important advantages of reading texts:

  • Reading characters in sentences shows you how to actually use Chinese characters, including grammar points.
  • Reading a story is much more fun and engaging than reviewing individual, out of context characters.

Most apps treat Chinese characters and words in isolation: reviewing one Chinese character does not influence the review of another. Reviewing a word does not affect your reviews for the characters contained in that word. Reviewing a sentence does not affect the reviews for the words and characters contained in that sentence.

Ignoring the intrinsic relationships between Chinese characters, words, and sentences is a missed opportunity to optimize your learning. Let's see below how we can do better.

Reviewing sentences to learn Chinese characters

MandarinBanana's review system is focusing on showing you sentences to keep track of the characters you know. Let's have a look at how this works.

Generating reviews

Whenever you visit a sentence on this page, MandarinBanana takes note of the characters and words you have seen in a sentence. As soon as you have seen a character or word in three different sentences, it's probably a good idea for you to learn it, and MandarinBanana will create a review for it. Subsequently, if you visit a sentence which has this character or word, their translations will be hidden. You can always click on it to get to the translation.

  • MandarinBanana knows which character you should learn from the sentences you have visited and will hide their translation. In this way, new sentences are always adjusted to your current learning level.
  • This means that you do not need to use the review system at all to continue learning! Just read new sentences or revisit old ones, and click on characters or words to show their translations if you need a reminder.


Once you have generated reviews for characters or words, a "continue" button appears at the top left of the page, which will take you to the next due review. How the next review is chosen is explained in detail further down below in the section "Choosing the next review". When a review is shown, you should remind yourself of the pronunciation and translation of every character on the page. When you then reveal the solution, you should judge if you did well or if you should relearn the information. The next due date of the review is chosen accordingly. What happens if you choose "relearn" is explained further below in the section "The failed review callback chain".

If you judge yourself to have understood and recalled everything well enough, you'll click on "continue" to get to the next review. The review due date will be adjusted to show it again in the far future. Additionally, if you reviewed a sentence and you didn't click on any character or word to be reminded of their translations or pronunciations, all reviews for all words and characters are "passed" as well, which means that their due dates are adjusted to be later in the future.

  • To review, hit the "continue" button at the top left of the page.
  • After being shown a character, word, or sentence, try to remember as much information as you can. After revealing the information, judge for yourself how well you did.
  • Choose "continue" if you remembered well. If not, choose "relearn" or click on any character or word to relearn it. When you're done refreshing your memory, hit "continue" in the upper left corner.
  • Reviewing sentences is a great way to track your progress for multiple different characters and words at the same time.

There's a second way to keep track of your reviews. Whenever you look up the translation of a character or word you have a review for, the review's due date is adjusted to be in the near future. It is assumed that since you had to look up a character or word, you probably forgot its pronunciation or translation, and it will be beneficial to remind you again after a short period of time.

Vertically integrated character reviews

There's more to utilizing the intrinsic relationships in Chinese characters to optimize your learning.

The key to reducing the grind of tens of thousands of reviews is to tap on the intrinsic properties of Chinese characters: on the one hand, almost all characters are built out of other characters (their components). On the other hand, many characters themselves act as components of other Chinese characters. Lastly, Chinese words are made out of Chinese characters.

That means there's no point in showing you a review for a character which has due reviews for one of its components, and the same is valid for words with characters you have due reviews for. Review the components first, then work your way up to the more complex characters and words.

Additionally, when you need to relearn a character or word, you should probably revisit their components just as a reminder. It will help you to remember the character or word more easier in the future.

  • MandarinBanana takes into account and adjusts the reviews for components and appearances of characters and words.

The review relearn callback chain

Here's a detailed account what actually happens when you click on "relearn" after being shown a review.

If you would like to relearn a sentence, you'll be redirected to the sentence's page where you can look up the vocabulary items and other details. You can click on characters or words you forgot to refresh your memory.

If you would like to relearn a word or character, you'll be redirected to their respective pages.

No matter how you ended up on a page for a word or character, the corresponding review's due date will be lowered so that you get a reminder after a short while.

The app will find three sentences you haven't seen in a while and schedule them to be shown to you soon to remind you how the character or word is used. This context will motivate you to actually remember it.

If the review is about a word, the app will help you to relearn each character in the word.

If the review is about a Chinese character, the app helps you relearn the components for that character, and relearn all characters the character in questions acts as a component in.

Choosing the next review

Usually, reviews in a spaced repetition software are scheduled by due date. MandarinBanana has a bit more complicated strategy to show you the most efficient next review.

  • MandarinBanana always prefers to show you sentences to review instead of individual characters or words.

If the next due review is a Chinese character review, try to find any due sentence reviews with the character and show one of them. If not, show the review for the character.

If the next due review is a word review, try to find any due sentence reviews with the word and show one of them. If any characters used in the word have due reviews, show those first. Otherwise, show the word review.

If the next due review is a sentence review, only show it if it has due character or word reviews. If there aren't, schedule this review for tomorrow, and try to find another next review.


The review system is focussing on sentence reviews to make reviewing Chinese more fun and engaging as well as more effective than traditional SRS systems at the same time. I hope you'll enjoy it as much as I do! You can sign up for a free account to try it out using the link at the top of the page. Just go through the sentences of a deck to start tracking your progress.

What do you think of the explanations on this page? Do you have any tips on how to improve it? Please let me know by sending an email to