First notebook entry: Introducing myself

Hi, my name is Sebastian. I am from Medellin-Colombia.
I have I am 21 years old, and I study Sistems Systems Engineering (or "I am studying Systems Engineering"). 

When discussing age, English speakers tend to use the verb "to be" rather than the verb "to have". Moreover, "years old" can be omitted. For example: She is twenty years old. He is almost seventy years old (or "He is almost seventy"). I am eighteen years old (or "I am eighteen"). We are not five years old (or "We are not five"). Good luck with your English studies! It is an easy language to learn, but it is most certainly a difficult language to master. If you stick with it, I am sure you will do both! :)

First notebook entry: Introducing myself

Hi, my name is Sebastian. I am from Medellin-Colombia.
I have 21 years old and study Sistems Engineering

it's so bad ! lol