3 Kid-Friendly Rephrasings of 'Underground trains run in city tunnels and they are the quickest way to get around' — Age 7

Here are three simple ways to say that:

1. Trains go under the city in tunnels, and they are the fastest way to get around.
2. Big trains run inside tunnels beneath the city, and they take people places the quickest.
3. Underground trains move through city tunnels, so you can travel around faster than other ways.

How I changed the sentence (easy steps):

1. I used short, clear words so it is easy to read.
2. I kept the two main ideas: trains are under the city in tunnels, and they are very fast.
3. I tried different word orders so you have three choices to use when talking about it.