应该说当这四个词均作花费讲时,pay和spend通常都是人做主语,take,cost通常是物作主语
pay+money+for+sth.
为某物支付多少钱
spend…on+sth在某物上花费…
spend…(in) doing sth做某事花费多少时间
如：I paid 5 yuan for the card
I spend 3 hour on my homework last night
I spent an hour (in) reading
I spend 15 yuan on the book
The book cost me 15 yuan
take通常用来……花费了多少时间,通常有以下句型
It takes/took sb +一段时间＋to do sth
比如：It took me three hours to find your home.
cost 表示“花钱,付出代价”
比如：The chair costed me 40yuan.
Dangerous driving could cost you your life.开车不注意安全有生命危险.
