The set expression 按说
We use the set expression 按说 
to make an assumption or express a point of view which is based on our own experience or common sense.
We should state it before a subject or a predicate.
to make an assumption or express a point of view which is based on our own experience or common sense.
We should state it before a subject or a predicate.Examples
他按说应该在家
He's supposed to be at home
tā ànshuō yīnggāi zài jiā
按说我们应该赢
We're supposed to win
ànshuō wǒmen yīnggāi yíng
这么大的孩子，按说该懂事了
A child of this age should know how to behave
zhème dà de háizi, ànshuō gāi dǒng shì le
We usually use the set expression 按说 with an adversative conjunction meaning “but”.
Examples include 可 , 可是 , 但是 , or 不过 . Each of these adversative conjunctions introduce the opposite idea of what was stated.
, 可是 , 但是 , or 不过 . Each of these adversative conjunctions introduce the opposite idea of what was stated.Examples
按说现在是春天，可是天气还是很冷
It is supposed to be spring, but the weather is still very cold
ànshuō xiànzài shì chūntiān, kěshì tiānqì háishi hěn lěng
按说这部电影应该很受欢迎的，不过没有人喜欢
This movie is supposed to be very popular, but no one likes it
ànshuō zhè bù diànyǐng yīnggāi hěn shòu huānyíng de, búguò méi yǒu rén xǐhuan
按说这次合作对双方都有收益，我就是不懂他们怎么不接受呢
This collaboration is supposed to be beneficial for both sides. I don't understand why they don't accept it
ànshuō zhè cì hézuò duì shuāng fāng dōu yǒu shōuyì, wǒ jiù shì bù dǒng tāmen zěnme bù jiēshòu ne