on last weekend 要+介词on吗?why?

on last weekend 要+介词on吗?why? on sunday evening、last weekend、汉语是什么意思! on last weekend这样说对吗?为什么? weekend什么时候要加介词?我好像看到过this weekend,on weekends,at weekends what happened on "Young Lives"last night?这句中为什么要用介词on?谢谢 what happened on "Young Lives"last night?这句中为什么要用介词on? What did you do on your last week?这句话正确吗?介词on要不要加呢? last weekend 前要不要加in或者on这种东东捏? last weekend,mike was very busy.on saturday morning,he______ what did you do last weekend?____went on a picnic. Last weekend,we plan to go on an outing on last weekend,I visited an old friend