一、it
强调句型的构成：It+be+被强调部分+that(强调部分指人做主语时时用who，指人做宾语时用whom)+句子的其他部分。例如：Mary met an old beggar in the street yesterday.It was Mary who/that met an old beggar in the street yesterday.(强调主语)It was an old beggar whom/that Mary met in the street yesterday.(强调宾语)It was yesterday that Mary met an old beggar in the street.(强调时间状语)It was in the street that Mary met an old beggar yesterday.(强调地点状语)注意：it强调句型不能强调句子的谓语。二、not…until结构强调句型的构成：It+be+not+until部分+that+句子的其他部分。例如：He didn't go to bed until his father came back..变为强调句型为：It was not until his father came back that he went to bed.注意原句中的didn't go部分中的not提前后，剩下did go变为went.本文开头提到的两个句子都是not..until结构用于强调句型。那么把这两句话变回正常的语序则为：1)…but he didn't make his most important discovery until after the war.2)The importance of Fleming's discovery was not fully recognized until World War II.三、
特殊疑问句强调句型的构成：
特殊疑问词+be+it+that+句子的其他部分(用陈述语序)例如：When did you receive the gift？对特殊疑问词when做强调：When was it that you received the gift？注意此句中的received是由did加receive结合而成的。