I'm writing about two simple and useful words in Mandarin Chinese that you can use on a daily basis to describe things that are fast or slow. These terms, "龟速 (guīsù) slow" and "神速 (shénsù) fast", I learned when reading and discussing Children's stories in my beginner Mandarin class.
Aesop's fable of The Tortoise and the Hare is one of the most famous folktales in the world and has been adapted to countless cultures and languages worldwide. The story is a lesson on speed vs. consistency. The hare, or rabbit, represents speed, while the tortoise, or turtle, represents consistency and slowness.
The Tortoise and the Hare was one of the first of many children's stories that I learned in China while studying Mandarin Chinese. Since I was already familiar with the story in English, I was able to compare the Mandarin version with the English version to better understand the usefulness of the Mandarin Chinese words and the way the two languages can express the same story using completely different methods. Our Mandarin Chinese teacher introduced two antonyms while we discussed the story after reading. These two words have stuck with me from then on. The words were 龟速 (guīsù) and 神速 (shénsù). The origin of the words is simple:
速 (sù) can be used as an adjective meaning "fast" and as a noun meaning "speed."
龟 (guī) = tortoise or turtle.
When we combine 龟 (guī) and 速 (sù), we get:
龟速 (guīsù) = slow (adjective); slowness (noun).
On the other hand, when we add "神 (shén) god/supernatural being" + "速 (sù) speed" we get 神速 (shénsù), meaning very fast (adjective); quickness (noun).
When using 龟速 (guīsù) and 神速 (shénsù) in a sentence, we can describe how daily conveniences and services may be moving quickly or slowly...Read more 
