请大家帮我翻译4个句子,这4句是我从书上摘抄的,讲语法的,对我很重要的.谢谢!

请大家帮我翻译4个句子,这4句是我从书上摘抄的,讲语法的,对我很重要的.谢谢!
1.We use the past simple with expressions such as last week, a year ago, yesterday(refering to time completely in the past)
2.We often use the present perfect simple with for and since(the period of time is from the past to now).
3.We usually use the present perfect simple with just, already and yet (words that have a link with now).
4.We often use the present perfect simple with ever and never (refering to any time up to now).