Monica and Sophia asked me to have a drink with them.I said

had enjoyed 是过去完成时,表示这个动作截止到过去某个时间已经完成.
楼主那句话中应该有错误,yuans 应为 years
这句话意思是：Monica 和 Sophia 请我我和他们去喝一杯.我说,离我上次好好的喝上一杯已经有10年了.
since + 现在完成时或者过去完成时,表示“从……起”.