I was asking them what kind of shampoo they bought and if they preferred brand X to brand Y.

我问他们买什么样的洗发水，相比品牌Y他们是不是更喜欢品牌X。

I was asking them what kind of shampoo they'd bought and if they preferred brand X to brand Y.

我问他们买了什么样的洗发水，他们是否更喜欢X品牌而不是Y品牌。

I was asking them what kind of shampoo they'd bought and if they preferred brand X to brand Y. Then I'd make up a report and the agency would use the information in their advertising campaigns.

我问他们买了哪种洗发水，以及他们是否更喜欢 X 品牌而不是 Y 品牌。然后我会编写一份报告，该机构会在广告活动中使用这些信息。