It was not until ... that ..., sau "that" nhớ bỏ (didn't) nhưng các trường hợp (couldn't/ weren't/ wasn't/ hadn't) sau that chỉ bỏ "not" mà thôi.
51. The boy didn't do his homework until his father came home.
-> It __________________________________________________
52. He couldn't go to school until his father came home.
-> It .....................................................................................................
53. Lan couldn't study English until she was 15.
-> It .....................................................................................................
54. Nam could not buy a house of his dream until he was forty.
-> It ......................................................................................................
55. She hadn't been a good teacher before she taught at the university.
-> It ........................................................................................................
56. He hadn't been a bad husband before he got married Marry.
-> It ..........................................................................................................
57. Anna wasn't punished until her manager knew the truth.
-> It ............................................................................................................
58. Hieu didn't study hard until he failed this exam.
-> It
51. It wasn't until his father came home that the boy did his homework
52. It wasn't until his father came home that he could go to school
53. It wasn't until she was 15 that Lan could study English
54. It wasn't until he was forty that Nam could buy a house of his dream
55. It wasn't until she taught at the university that she had been a good teacher
56. It wasn't until he married Marry that he had been a bad husband
57. It wasn't until her manager knew the truth that Anna was punished
58. It wasn't until he failed this exam that Hieu studied hard.
