I've decided to lose weight/ I decided to lose weight. They are quite similar. So you can say both of them at any situation. If I am wrong, I hope others can correct me :)

I always read newspapers in the mornings. 

I always read newspapers in the morning

Do you play tennic seldom? 

He doesn't often see TV in sunday.

 He doesn't watch TV on sundays.

They sometimes play hockey. 

Is this cake tasty? 

He quite often drink coffee in the evening. 

He drinks coffee quite often in the evening 

Why he is so sad on sunday? He isn't sad he is boring. 

Why is he so sad on sundays? He's not sad, he is boring

He is very shy that's why he is boring. 
I have a headache. 
We have a breakfast every day. 
Have you always a dinner at home. 

Have you always had dinner at home?

I have not often a breakfast on the street.

I  often don't have breakfast on the street 

Do you want to go to a concert with me هل تريد الذهاب الى الحفل معي؟ Yes, I'd love to نعم، اريد الذهاب Let's meet at 7 pm سوف نتلاقى في السابعة مساءً I learn foreign languages and I want to become a translator انا اتعلم لغة اخرى و اريد ان اكون مترجمة

About my English studying

My English studying is not going well.
I think it is reasonable.
Because I'm a(type of) person who is not very willing to speak.
Everyday, I speak Chinese to people. My voice is not loud and clear, seems(like) I'm afraid and nervous.
Sometimes I take too much time to think(ing not needed) about it before I open my mouth to talk to people.
These are not good characteristics. I will try to overcome it.