Mary: Today I woke up at 7:50.

Correct: Today, I woke up at 7:50 in the morning.

Explanation: Place a comma after certain introductory elements. Like "Today," "Then," "Afterwards," etc. We can also use prepositions in expression of time to enhance our sentence like: in the morning, in the afternoon, in the evening, at night, etc.

Mary: Then I stuy with my Chines teacher. I learn lots of thing in my Chines class. Then I study math.

Correct: Then, I studied with my Chinese teacher. learned lots of things in my Chinese class. Then, I studied Math.

Explanation: Since it's already done, we use the past tense of the verb like: study>studied, learn>learned, have>had, and brush>brushed. And please take note that the spelling of Chinese is C-H-I-N-E-S-E.

Mary: Then my mother went to my sister's friend house because she have to fix my father's phone.

Correct: Afterwards, my mother went to my sister's friend's house because she had to fix my father's phone.

Explanation: We use friend's to imply that the house is owned by your sister's friend.

Mary: And we ate luch afrtwe that my sister bought ice-cream.We ate yummy ice-cream and brush our teeth. Then I study with my teather called Monica.

Correct: And we ate lunch. After that my sister bought ice cream. We ate yummy ice cream and brushed our teeth. Then, I studied with my teacher called named Monica.

Explanation: We don't use dash in the word ice cream, but we use them usually in phone numbers like: 408-555-6792, to indicate a range of numbers like: 12-24, or to show a time frame like: 1993-2014.

*Hello, Mary~! You study a lot, everyday, I think you really deserve 3 stars! Please continue your eagerness in class. Thank you. Carry on. :)