one word
two words
three or more
100

My mom's name is mary

My mom's name is Mary (propper name)

100

She's Susan, my Brother's girlfriend.

Incorrect. The word brother should't be capitalized. 

100

Jhon lenon and  Ringo star are my favorite beatles. 

Inconrrect. Names and lastnames should be capitalized. 

200

The doctor called grandpa for a check up

The doctor called Granpa for a check up (acts like a propper name)

200

All people on earth should speak English

Correct. First letter on a sentece and capitalization of the noun English

200

people in the united states and the united kigndom speak english 

People in the United States and the United Kingdom speak English.

300

at he end of the movie, everybody was excited.

At the end of the movie, everybody was exited. (Begginig of the sentence)

300

my parents and i always go on weekends to eat Chinese food.

Wrong. My parents and I .. the pronoun I is always  capitalized. 

300

option a) During Summer we always go to the beach on Fridays, but in Winter we prefer to go to the Mountains on Mondays.

option b) During summer we always go to the beach on Fridays, but in Winter we prefer to go to the mountains on Mondays.

Option b is correct. Seasons are not capitalized.

400

Capitalized the names of the planets, constallations, stars and all kind of heavenly bodies. 

TRUE

400

Do we capitilize nationalities? Even when we're talking about food? For example: Michael and Susan love Italian food.

Yes. Nationalities should capitalized.

400
senator james will speak in french in the conference.

Senator James will speak in French in the conference. (person's title should be capitalized when is part f the name)

500

You should always capitalized the word Earth. 

False. Only when is wrttien along with other planets or heavenly bodies. 
500

united nations (un) declaration of human rights.

United Nations (UN) declaration of human rights.

500

dr sara cooper is my favorite doctor. although all doctors at general hospital are really good.

Dr. Sara Cooper is my favorite doctor. Although all doctors at General Hospital are really good.