Soon means ‘a short time after now’.
- Get well soon. (NOT Get well early.)
- We will launch a new edition of this book sometime soon.
Soon can also mean ‘a short time after then’.
- It was difficult in the beginning, but I soon got used to it. (NOT It was difficult in the beginning, but I early got used to it.)
Early means ‘near the beginning of a period of time we are talking about’. Early does not mean soon.
- Early this week, I had a strange experience. (NOT Soon this week, I had a strange experience.)
- He had an accident early this month.
- He will soon have an accident if he continues to drive like this. (NOT He will early have an accident…)
- I get up early in the morning. (NOT I get up soon in the morning.)
Early can mean ‘before the expected time’.
- I arrived early.
Early can be used as an adjective.
- We will be grateful for an early reply.
There is a difference between soon and quickly. We use quickly to refer to the speed with which something is done. Soon means ‘before long’.
- I got dressed quickly. (= I didn’t take a lot of time to get dressed.)