1.left的基本意思是“左”,可指“左边,左侧,左部”,是不可数名词。
2.表示“左翼,社会主义拥护者”时,常与the连用,且大写,是集体名词;在强调整体时,谓语动词用单数形式;强调成员个体时,谓语动词用复数形式。

Make a left at the corner.到下一个拐角处向左拐。
Go down the street and then turn to the left in the end.顺着这条街走到头,然后向左拐。
Each line is flush on the left with the lines about and below.每一行的左边都上下对齐。
I caught him on the chin with a straight left.我用左直拳击中他的下巴。
The Left opposes the new taxes.左派反对征新税。

on〔at〕 sb's left, to sb's left
on〔at〕 sb's left表示“紧靠在…的左边”; to sb's left表示“在某人左边稍远的地方”,有一段距离。例如:
Stuat sat on my left.
斯图亚特紧靠着我的左侧坐着。
(紧挨着左边坐)
Stuat sat to my left.
斯图亚特坐在我的左侧。
(坐在左边,但不一定紧挨着)

1.left的基本意思是“左侧的,左边的,左面的,左方的”,在句中常作定语。引申则表示“左翼的,左倾的”,在句中常作表语。
2.left只有表示“左翼的,左倾的”时,才有比较级和最高级(lefter, leftest或more left, most left)。

have two left feet
非常笨拙 be very clumsy
I never learned to dance because I've got two left feet.我从来就没学会跳舞,因为我的动作极其笨拙。

用作定语
▲～+n.
 Not many people can write with the left hand.用左手写字的人并不多。
Was he blind in the right eye and lame in the left foot?他是不是右眼瞎、左脚瘸?
My house is on the left side of the street.我的家在这条街的左侧。
The pages on the left side of a book have even numbers.一本书的左页页码是偶数。
Our company made a sudden charge on the left wing of the enemy.我们连对敌人左翼发动了突袭。
用作表语
▲S+be+～
 He is very left.他很激进。

left还可作副词,表示“向左,在左边(towards or in favor of the left)”。例如:
He looked left and right.他左右看看。
Eyes left.向左看齐!
Left turn.向左转!
I've been looking for it left, right and centre—where did you find it?我前后左右都找遍了——你是在哪儿找到的?
I seem to have disappointed them left, right and centre recently.最近，我似乎在各方面都使他们失望。

［同义词］ adj.  communist, left-hand, left-wing
［反义词］ n. & adj.  right