有since引导时间状语从句的句子中,主句的时态是否可用一般现在时态?
要是it's 2 years since i last saw you.我还可以理解.口语说法嘛.
但是900句里面有个句子：We are friends since primary school.不明白怎么会是are,不是have been?期待合理解释.