Answer:
Step 1: Figure out the riddle
1.) Your shadow, it's as big as you are but doesn't weigh anything.
2.) Your breath, you can hold it without using your hands and arms.
3.) A stamp, it travels the world but stays on the mail that it was stamped on.
4.) A river, it's all of those things.
5.) The letter 'I', because it's in the middle of the word.
6.) A Teapot, it starts with a 't' and ends with a 't' and has tea in it.
7.) A Clock, it has two hands but it cannot clap.
8.) A Blackboard, it gets more white the more you draw on it, it gets dirty.
9.) February, it is the only month that has 28 days.
10.) Riverbank, get it :D a riverbank lol
I had a harder time spelling February then answering these riddle. Thanks!