两个意思都很接近,可是用法可就不一样了.
take
interest：没加上an的话,就是可以指很多样,对很多样事情有兴趣.我给一个例子：I take interest in playing
badminton and swimming～；
take an interest：加上an就是指一个而已,对一个事情有兴趣而已.我给一个例子：I
take an interest in playing badminton only～
take interest in和take an interest in区别
take interest in 和 take an interest in 的区别在于语义表达。
take an interest in
是习惯用法（idiomatic usage），有固定的词义：对（某事/某人）有兴趣，表达关注，相当于 be interested in。而 take
interest in 不是惯用法，只是因语义表达需要而将单词用在一起：从（
商业利益）中收取利息。这个表达方式中的 interest
是不可数握磨名词，通常用来表达从投资或
银行存款中获取的利息。例：
You should take an interest in everything your
child does. 你应该关注你孩子所做的每件事。
I have/take interest in a restaurant.
我从一家餐馆获取利息/利益。
需要注意的是，take an interest in 在某些特定的语境中会将 an 省略，比如：
He lost
his interest in life long ago. Wealth, love, and happiness meant nothing to him.
He took interest in neither of them.
上例中的 took interest in 用于否定语义的句子中（= He
took no interest in them）。
take interest in和show interest in的区别
take interest in
英[teik ˈintrist in]美[tek ˈɪntrɪst
ɪn]
释义：对…感（产生）兴液皮毁趣
网络：对……感兴趣; 流行
音乐不感兴趣了; 感兴趣
show interest
in
英[ʃəu ˈintrist in]美[ʃo ˈɪntrɪst ɪn]
释义：对…有兴趣闹备; 理睬
网络：对…感兴趣;
感兴趣
例句
1 Nice of you to take interest in my
heaith.
谢谢你还关系我的
健康状况。
2 The power of least interest can cause people to
cloak themselves in indifference rather than take the effort and the risks
needed to build relationships based on
trust.
最低兴趣方所拥有的权力可能会导致人们用冷漠的假象隐蔽自我，而不是采取必要行动、承担必要风险，在信任的基础上建构人际关系。
3 More
and more westerners show interest in Confucianism.
越来越多的西方人对儒教产生兴趣。
4 He
liked started to show interest in me.
他开始表现出对我的兴趣。