Q;Do you like being a leader? Why and why not?

A: I don't like being a leader, because I have to take a lot of responsibility. 

=> Corrected: The sentence is corrected grammatically. 

-엔지니어는 무슨 일을 하나요?

What engineers do? =>What does an engineers usually do? => Corrected: The sentence is corrected grammatically.​

-엔지니어는 보통 다리를 설계한단다.

Usually, the engineer designs bridge. => An engineer usually designs bridges.  => Corrected: The sentence is corrected grammatically.​

-우와! 멋져요. 나도 엔지니어가 될 거예요.

Wow! It's cool. I'll be engineer too. =>Wow, wonderful! I want to be an engineer.  => Corrected: The sentence is corrected grammatically.​​