Not my mother, it's my sister who/that does the shopping.

[Luis Flmg]

1 - Is it your mother who/that does the shopping, Luis?
2 - Not my mother. It's my sister who does it.
3 - Was it yesterday when/that you bought that T-shirt?
4 - Not yesterday, it was last month.
5 - Was it on Monday that you saw Mary?
6 - Not (on) Monday. It was (on) Tuesday.
7 - Is it in Rio that/where you usually spend your vacations?
8 - Not (in) Rio. I go to Bahia.

Are the sentences above correct?

 

[emsr2d2]

They're all OK in casual, conversational everyday English. Don't use them in formal or exam settings.

#4 needs either a colon or a full stop after "yesterday". Currently, you have a comma splice.

 

[jutfrank]

They're all OK in casual, conversational everyday English. Don't use them in formal or exam settings.

Would you clarify what you mean? Do you mean that in every case that is okay in casual speech?

 

[emsr2d2]

Would you clarify what you mean? Do you mean that in every case that is okay in casual speech?

You'll certainly hear native BrE speakers use "that" in #1.
"That" is certainly better than "when" in #3. Those were the only two sentences in which the OP queried the use of "that".
I have only just noticed that #7 uses "that/where". They weren't in bold so I didn't look at them. "That" is the only of them that works for a question starting "Is it in Rio ...".

 

[jutfrank]

You'll certainly hear native BrE speakers use "that" in #1.

Yes, right. I understood that you were saying that that is okay in casual speech, even though who is the more normal word. In fact, I took you to be saying the same in all cases, 1, 3 and 7.

"That" is certainly better than "when" in #3.

Yes.

I have only just noticed that #7 uses "that/where". They weren't in bold so I didn't look at them. "That" is the only of them that works for a question starting "Is it in Rio ...".

That's exactly what I was going to mention so I wanted to clarify with you. Yes, Rio and in Rio are quite different.

 

[Tarheel]

I've read it several times, and I don't see anything wrong with "when" in number three. In fact, in seems like a variant on "When did you buy that ...?"

 

[Luis Flmg]

Could anybody kindly write down the best variants for each of the 8 sentences? I'd really appreciate that.

 

[emsr2d2]

Could anybody kindly write down the best variants for each of the 8 sentences? I'd really appreciate that.

Do you mean the best choice in each sentence while not changing any of the other words?

 

[Luis Flmg]

Yes, precisely!

 

[emsr2d2]

1 - Is it your mother who does the shopping, Luis?
2 - Not my mother. It's my sister who does it.
3 - Was it yesterday that you bought that T-shirt?
4 - Not yesterday; it was last month.
5 - Was it [on] Monday that you saw Mary?
6 - Not [on] Monday. It was [on] Tuesday.
7 - Is it in Rio that you usually spend your vacations?
8 - Not (in) Rio. I go to Bahia.

I have left in the more natural option in each sentence and made a couple of other markups.

 

[Tarheel]

I suppose it's some kind of exercise, but more natural for #1 would be, "Does your mother do the shopping?" Also, in speech the answers are likely to be shorter.

 

[Luis Flmg]

It's not an exercise at all. I'm just trying to understand this pattern "It is/It was....... that/who/when/where........?". The sentences could have been any, I came up with them. I made out the explanations, but it's not easy for me to understand the rules.