Sunday

I am rest in my house now because I was a hard week, it began with some math tests on monday and tuesday, on wednesday I did my end homework for the university on thursday and friday I studied for my English test and in the afternoon I went to class, yesterday I stayed at home with my friends and we watched the match Colombia-Greece, it was wonderfull!!! we was celebrated during all day!

I am staying (or resting) in my house now because I had a hard week. It began with some maths tests on monday and tuesday; on Wednesday I did my final homework for the university, on Thursday and Friday I studied for my English test and in the afternoon I went to class. Yesterday I stayed at home with my friends and we watched the Columbia -Greece !atch: it was wonderful!! we were celebrating all day 

Sunday

I am resting in my house now because I have had a hard week; it began with some math tests on monday and tuesday. On wednesday, I did my last homework for the university. On thursday and friday, I studied for my English test and in the afternoon I went to class. Yesterday,I stayed at home with my friends and we watched the match Colombia-Greece. It was wonderfull! We were celebrating all day!

Sunday

I rest in my house now because I had a hard week, it began with some math tests on monday and tuesday, on wednesday I did my final homework for the university on thursday and friday I studied for my English test and in the afternoon I went to class, yesterday I stayed at home with my friends and watched the match Colombia-Greece, it was wonderfull!!! we celebrated during all day!

Sunday

I am resting in my house now because I was had a hard week,; it began with some maths tests on mMonday and tTuesday, on wWednesday I did my end homework for the university and on tThursday and fFriday I studied for my English test and in the afternoon I went to class,. yYesterday, I stayed at home with my friends and we watched the match in which Colombia were playing Greece, - it was wonderfull!!! wWe was were celebrated celebrating during all day!

Good! You have made many mistakes with capitalization. Days of the week, in English, are proper nouns. You must also always use a capital letter after a full stop (period) "."

-In America they refer to the numerical school subject as math and in England we call it maths. What you've written isn't wrong, however.