Okay, so imagine that there are two groups of people who want to talk to each other, but they don't speak the same language. This used to be a problem for the people in a place called Kyakhta, which is in between Russia and China. The Russians spoke Russian, and the Chinese people spoke Chinese. But they really wanted to trade and communicate with each other, so they had to find a way to understand each other.
To solve this problem, they created something called a pidgin language. A pidgin is a simplified form of a language that is made by combining words and rules from different languages. It's like a mix of two languages that helps people communicate when they don't speak the same language.
In the case of the Kyakhta Russian-Chinese pidgin, it was a mix of Russian and Chinese words and grammar. They took some words from Russian and some words from Chinese, and put them together in a way that both groups of people could understand.
For example, let's say the Russian word for "hello" is "privet" and the Chinese word for "hello" is "ni hao". Instead of using either of those words, they might come up with a new word like "privet-ni hao" that both Russian and Chinese people could understand.
The same thing happened with other words too. They would take words from both languages and create new words that everyone could understand. It was kind of like making a secret code that only the people in Kyakhta could understand.
They also had to come up with new rules for how to use the pidgin language. For example, in Russian and Chinese, you have to change the word depending on if it is past tense or future tense. But in the pidgin language, they might use the same word for both past and future tense to keep things simple.
The Kyakhta Russian-Chinese pidgin was used for many years as a way for the Russian and Chinese people to trade and communicate with each other. It helped them understand each other and build relationships, even though they didn't speak the same language.
So, in simple terms, the Kyakhta Russian-Chinese pidgin was a special language made by mixing Russian and Chinese words and rules. It helped people in Kyakhta understand each other and trade, even though they spoke different languages.