verb + downwards
downwards 强调方向，非正式场合常可用 down 替换。
She looked downwards at the ground.
她向下看着地面。
趋于下降；朝较低水平；向下；朝下方。；从高处到低处；向较低、较小、较劣等方向。
towards a lower place or position, either physically or metaphorically
向下；朝下方。
Towards a lower place; towards what is below.
从高处到低处
spatially or metaphorically from a higher to a lower level or position
向较低、较小、较劣等方向。
Towards something which is lower in order, smaller, inferior, etc.
The plane began to descend downwards towards the runway.
飞机开始向下朝跑道降落。
用法提示：副词表示向低处移动的方向。
She looked downwards to avoid eye contact.
她向下看以避免目光接触。
用法提示：副词表示视线朝下的方向。
The trend in prices has been moving downwards for months.
几个月来价格趋势一直在向下移动。
用法提示：副词表示趋势向下降的方向。
downwards 强调方向，非正式场合常可用 down 替换。
She looked downwards at the ground.
她向下看着地面。
常见于经济或趋势描述。
The stock price trended downwards.
股价呈下降趋势。
最常用，口语或书面均可；与downwards几乎同义，但downwards更正式或强调方向
与downwards同义，但downward可作形容词；作副词时比downwards稍正式
通常指物理上的向下斜坡或比喻中的衰退；不能完全替代downwards用于所有语境
grammar · medium
易错句子He walked downwards the hill.
正确表达He walked down the hill.
downwards 是副词，不能直接接宾语。要表示‘沿着...向下’时，需用介词 down 引导方向名词。
grammar · medium
易错句子a downwards slope
正确表达a downward slope
downwards 是副词，不能修饰名词。应用形容词 downward 来修饰名词。
grammar · medium
易错句子Downwards he looked.
正确表达He looked downwards.
副词 downwards 通常置于动词之后，放在句首虽语法正确但语序不自然，不符合英语惯用表达。
“downwards”指朝较低位置或水平移动（空间或比喻义），其直接反义词是“upwards”（朝较高位置）。二者在多数空间及比喻用法中可互换；注意“upward”为“upwards”的变体拼写，词性同为副词。
downward 是形容词，修饰名词；downwards 是副词，修饰动词。
down 作为副词更通用，常与动词搭配（go down）；downwards 强调方向性，多用于正式或书面语。
向下移动
The elevator moved downwards slowly.
电梯缓慢地向下移动。
向下走
We need to go downwards to reach the exit.
我们需要向下走才能到达出口。
向下倾斜
The path slopes downwards towards the river.
这条小路向下倾斜，通往河边。
指向下方
The arrow on the sign points downwards.
标志上的箭头指向下方。
向下流
Water flows downwards due to gravity.
水因重力而向下流动。
向下看
She looked downwards to avoid eye contact.
她向下看以避免目光接触。
down
-wards
恶性循环；螺旋式下降
The economy is spiralling downwards into a recession.
经济正螺旋式下滑，陷入衰退。
向下流动（社会地位下降）
He experienced downward mobility after losing his high-paying job.
失去高薪工作后，他经历了社会地位的下降。
下降趋势
There is a consistent downward trend in the stock market.
股市呈现持续的下降趋势。
Dictionary facts from ECDICT, WIKTIONARY.