[Grammar] why present perfect tense is used here?

[rock-onn]

In my study text an example is given which is a fictional one. It uses present perfect tense.

A sporting venue has used linear regression to examine the relationship between hot drink sales and match day attendances as follows:


This is the first sentence of the example given.

Why did they use present perfect tense?

 

[rock-onn]

Note that your question should be: Why is (the) present perfect used here?

I didn't understand why should I use present tense to ask that question. My reasoning is that it is already done by them and so past tense looks right for me. English grammar is tough.

 

[GoesStation]

Write I don't understand why I should use present tense to ask that question. You have to invert subject and verb after a question word when the phrase is a question. When it's a statement, don't invert them. Forming questions in English is tough, too, isn't it?

We use the present tense to ask questions when we're asking about habitual or repeated actions or an ongoing condition. I changed the tense in your question about asking questions because you're asking about an ongoing state.