英语句子呈“树”状铺排，即以主语与谓语动词的SV搭配形成形式主轴，即句子的主干部分，“然后利用各种关联词和介词等把句中的各种短语(介词短语、名词短语)、附加成分(同位语、插入语)、分句(现在分词分句、独立成分)和从句(定语从句、状语从句、同位语从句)往这根主干上钩搭，犹如一棵枝叶横生的大树，盘根错节十分复杂”。 例1：This is the cat
that killed the rat that ate the
malt that lay in
the house that Jack built.一句中，“This is
the cat ”是句子的主干，而“that killed the rat”、“that ate the malt”、“that
lay in the house”以及“that Jack
built”都是定语从句，分别修饰各自的先行词“cat”、“rat”、“malt”和“house”，这几个定语从句就像是横生的枝叶，伸展于“This
is the cat ”这一主干之上。
译文：这是那只杀死老鼠（它偷吃了放在杰克房间的麦芽）的猫。 例2: The fact that many family organizations
are not monogamous, as in the
west, led many nineteenth-century observers to the erroneous conclusion that in “early” stages of evolution there existed no families,and that “group marriage,” institutionalized
promiscuity, prevailed. 难点单词 monogamous[mɔ'nɔdʒeməs] 一夫一妻制的 erroneous[i'rəunjəs]
不正确的；错误的 institutionalized[,instə'tju:ʃənlaizd](习惯等)被确立的,
被接受的 promiscuity[,prɔmis'kju:iti]
混乱 institutionalized promiscuity
制度上的一夫多妻制 句子的主干结构为The fact …led
…observers to…the conclusion…；其中主语the fact带有一个同位语从句that many family
organizations are not monogenic，宾语the conclusion带有两个同位语从句，分别是that
in “early” stages of evolution there
existed no families, 和that “groupmarriage,” institutionalized promiscuity, prevailed；主语the fact和谓语动词 led之间是插入语as
in the west，而在最后一个同位语从句内，短语institutionalized promiscuity是 group
marriage的同位语。
