Thanks for the corrections! Here's a few more

I need to write a letter to my brother. - Я нужно писать писмо мой брату.
He bought milk and bread. - Он покупал молоко и хлеб.
My dog loves the sun. - Моя совака любит солнце.
His grandpa is a farmer. - Его дедушка фермер.

Thanks for the help!