They're both correct, but I'd say "I'm not afraid of the dark" is more natural and common.

I prefer to use a car, because you can move faster.

The most popular sport in my country is soccer (OR Soccer is the most popular sport in my country). It's something special. People are happy, and drink beer while watching the game.

I must write sentences about the organization of a company. I must choose my own company, the one that I’m working for. I have been working at Crédit Agricole for thirteen years. It’s a bank which is located all around the world. There are many employees. In France there is a board of directors with a president, a general director and different directors for different areas. Indeed, we need a marketing director, a sales director, a human resources director, a business director, and an accounts manager. It’s a big company that represents trade unions for protecting employees.

Hi Dreamy! I'm doing well. Welcome to italki! I'm a native English speaker and an italki community tutor. I offer (paid) conversation/writing/reading sessions over video call. Feel free to check out my teacher profile or send me a message if you're interested in booking some time with me :)

Hi Alina! I'm a native English speaker and an italki community tutor. Feel free to check out my teacher profile or send me a message if you're interested in booking a (paid) class with me sometime :)

Hi Lisa, I can definitely help! I'm a 21-year-old native English speaker and an italki community tutor. Feel free to check out my teacher profile or send me a message if you're interested in booking a (paid) class with me sometime :)