2．既往历(past history)：大半用过去式，但发生过去某一定时间以前者，宜用过去完成式；如果疾病发生的前后关系甚明显，或以年代顺序记载时，仍可用过去式。
1)A.过去式：用以表示过去的动作、状态、习惯等且与现在的情形毫无关联。
a)发生于过去某时者：
例1：An unknown number of years ago he was said to have pneumonia.
例2：In addition to the above symptoms, he noted some vague abdominal pain for a couple of months in the past.
例3：At that time she had a slight nonproductive cough and mild exertional dyspnea.
例4：Before therapy, she was unable to swallow anything but small sips of water.
b)过去某时以后的状态：
例1：In the previous month she noticed that the stools were greatly flattened. Subsequently she became aware of a bearing-down pain the rectum.
例2：Menarche occurred at age 13, thereafter menses were regular, every 28 days, lasting 3 to 4 days each time.
例3：The patient had tinnitus in his left ear 10 years before being discharged for the military service. Several year later, he noted loss of hearing on the left.
例4：In June 1956, a sterilizing operation was performed at a hospital. For the ensuing 5 months the patient was troubled with intermittent attacks of vague abdominal pain.
例5：Two years after this episode she had one short attack of vertigo but has been attack-free for 2 years.
注1：过去式常用的连用副词：ago, last night, yesterday, the day before yesterday, the other day, this morning , just now等。
注2：现在完成和过去两者都可用的连用副词：just, ever, lately, recently,
once, always, already, this morning, today, every night, this week, these few days, for the last few days, since last week, before, yet等。医学.全在.线www.med126.com
B.表示过去的习惯时，须用used to , was (were) accustomed to ~或had the habit to ~等。用would来表示过去的习惯时，大抵与often, sometimes等副词连用。
例1：He used to work far into the night.
例2：He would sometimes come home drunk, and beat his wife.
C.过去进行式( Be 动词的过去式+ pres. p.)：表示在过去某一时间正在进行 的动作：
例1：One sister was suffering from active tuberculosis.
例2：He was having mild symptoms of fever and nausea at the time he was seen.
例3：He was raising large amounts of purulent sputum at that time.
D.过去完成式( Had + p.p.)：表示截至过去某一时间为止的动作的完了、经验、继续等。
a)完了( completion)：
例1：The patient had already expired when he came.
例2：By that time he had immunized against smallpox.
连用副词：already, by that time, (not) yet, only just等。
b)经验(experience)：
例1：Till then he had never seen so-called bone-setter.
例2：He could not repeat what he had said before.
c)继续(continuance)：
例1：He had long been ill in bed.
例2：He had been ill in bed for a long time.
E.过去完成进行式(Had been + pres. p.)：表示继续过去某一时间的动作。
例1：Up to that time, he had been drinking mush wine.
例2：Due to her increasing constipation, she had been taking laxatives daily for one year before admission.
比较：
例1：I was sleeping when he came. (过去进行式)
例2：I had been sleeping for an hour before he came.(过去完成进行式)
