请问一个语法问题

we are walking along this street 可以
along就是介词了，

along
[E5lCN]
adv.
往前, 向前
prep.
顺着, 沿着

along
a.long
AHD:[…-lông“, …-l¼ng“]
D.J.[*6l%80, *6l%0]
K.K.[*6l%0, *6l$0]
prep.（介词）
Over the length of:
顺着：
walked along the path.
顺着小路走
On a line or course parallel and close to; continuously beside:
纵长地，平行地：沿着一条近处的平行线或道路；并排连续的：
rowed along the shore; the trees along the avenue.
沿着岸划船；沿街的树木
In accordance with:
根据：
The committee split along party lines over the issue.
由于各自坚持自己政党的路线，委员会在这个问题上产生分歧
adv.（副词）
Forward; onward:
向前；朝前：
We drove along, admiring the view. Farther along, we passed a hitchhiker.
我们一边开车，一边观赏风景。前面更远处，我们经过了一个要求搭便车的旅行者
As a companion:
作为伙伴：
Bring your friend along.
带你的朋友一起来
In accompaniment or association; together:
陪伴，相关；一起：
packed an atlas along with other books.See Usage Note at together
把地图册和其它书堆在一起参见 together
With one; at hand:
在手边；随身：
Luckily, I had my camera along. Our guests should be along soon.
很幸运，我随身带着照相机。我们的客人马上就到
Informal Advanced to some degree:
【非正式用语】 到达相当程度：
getting along in years.
上了年纪

可以写成we are walking along this street
但不能写成we are walking along of the stree

we are walking along this street可以
不能是we are walking along of the street.
along和of不能连用，