The simple past
I cleaned
It began and completed in the past without any connection with the present
Similar words and expressions include:-today=this morning=(9:00-10:25 )am.
washing clothing=cleaning=cleaned (my room)
no" since" used;
Hence:-
I cleaned my room this morning.
"I cleaned my room today." is ok
1. clean the room (整理房間) - 如果你將洗衫當成是整理房間的一項工作,用'cleaned my room' 係可以接受的,示乎你要幾詳情的描述。
2. 'Today' - 從午夜開始共廿四小時,這包括過去,現在和未來。你所描述的事情是發生在你說話時之前,所以pass tense係ok。
2015-03-21 18:13:20 補充:
似乎大家在比較緊"你今日食咗早餐未 vs 你今早食咗早餐未" 類似問題?
我自己就覺得兩者都可以,當然,"你今早食咗早餐未"係比較合邏輯D,但並不可說"你今日食咗早餐未"是錯的。只視乎說這話時的情況。