In my last holiday, I went to Hawaii. When I (go) (1) went to the beach for the first time, something wonderful happened. I (swim) (2) …was swimming ………in the sea while my mother was sleeping in the sun. My brother was building a sand castle and my father (drink) (3) ……was drinking ……. some water. Suddenly, I (see) (4) ……saw ……a boy on the beach.
$(2)(3)$ hành động diễn ra đồng thời trong QK
=> sử dụng QKTD: S+was/were +Ving
(1): hành động xảy ra trong QK và được kể lại
=> Sử dụng QKĐ:S+Ved/cột 2