If you're not already a member - come check us out!

[sitifan]

If you’re not already a member — come check us out!
Source: https://www.facebook.com/1000637662...u-are-a-member-invite-someo/1807201616011042/

Why not use "yet" in a negative clause as the sentence below?
If you’re not a member yet — come check us out!

 

[SoothingDave]

You could. Either expresses the idea.

 

[sitifan]

1. How can you be sure that I haven't already done my homework?
2. How can you be sure that I haven't done my homework yet?
What's the difference in meaning between the above two sentences?

 

[emsr2d2]

None.

 

[jutfrank]

1. How can you be sure that I haven't already done my homework?
2. How can you be sure that I haven't done my homework yet?
What's the difference in meaning between the above two sentences?

It's not a difference in meaning in the way you're thinking. The difference lies in how and why the questions could be used.

 

[SoothingDave]

As I said, either expresses the idea.

(Quoted from Gemini)​

In short: Sentence 1 argues that the homework might be done. Sentence 2 accepts that the homework is not done, but asks how the listener knew.

Nonsense. Both are asking the same thing "how can you be sure?" The phrasing of the rest is two ways of saying the same thing.

 

[5jj]

Don't trust Gemini.

 

[sitifan]

As I said, either expresses the idea.
Nonsense. Both are asking the same thing "how can you be sure?" The phrasing of the rest is two ways of saying the same thing.

Do the sentences below mean the same thing?
3. I haven't already finished my homework.
4. I haven't finished my homework yet.

 

[5jj]

3. is not natural.

 

[sitifan]

3. I haven't already finished my homework.
3. is not natural.

But 1 is natural, isn't it?
1. How can you be sure that I haven't already done my homework?

 

[5jj]

It's OK.

 

[jutfrank]

(Quoted from Gemini)​

In short: Sentence 1 argues that the homework might be done. Sentence 2 accepts that the homework is not done, but asks how the listener knew.

Why are you telling us what Gemini says? Do you want us to rate the answer? You sometimes quote AI in your threads and it's sometimes not clear to me what you mean by doing so.