Find examples of informal language in Anna's email. In an email to a friend, use informal language

Dear Luckyguy,

I was very glad to hear from you again. I have written a message to you quite recently and yesterday I got a letter from you .
I got your invitation to come to Moscow in September. That would be great! But unfortunately, I cannot come to  your place and have a fun with you and your friends. My older sister is going to come here with her husband and children. So I have to spend time with her kids (my cousins) and help my mother around the house. It is always so awful  when the house is full of guests even if they are your relatives.
I don't understand what you have written about "watchdog" but I think that you'll explain me this situation in your next letter. 
I wish you have a good holiday, relax and have fun.
That's for me today. I have to go to the swimming pool. 
Best regards to your family.
Write soon,
John

I’d like to start my composition with the words that Russia is a really great country. It is proved1 by the history of it,  its power in the modern world. The history of Russia dates back to  the 9-th century when Kiev, Vladimir and Novgorod were united with and formed an ancient Russia. In 988 it became a powerful Christian country. It was ruled by Tsar many years, but in 1917 after the revolution it bacame a communist country. Many countries were united together and it was named the USSR. But in 1991 this great country was broken up. There were a lot of historic events in the past, many wars which had ruined Russia but it was rebuilt again.