Will you be there at that time?
"at that time" is redundant, but completely acceptable in any circle except one specifically concerned with refined sentences.
"Will you be there?" already implies a moment in time. However, the moment is refered to indirectly; the direct reference is to where one will be.
The sentence structure occurs after a future, planned event has been mentioned. The time will have been indicated or assumed.
A better grammarian can explain it more complicatedly, which would be useful and interesting... to some people.
"Will you be there at that time?" is already a correct sentence. It is a polite way to ask if someone will be present at a specific time.
"He could not have been there" is the correct sentence. It conveys the idea that he was unable to have been at the specified place.
No, the correct sentence would be: "Is the sculpture free form?"
No, the sentence is not grammatically correct. A more correct version could be: "Why was she promoted?" or "She was promoted, but why?"
No, the sentence is not correct. It should be "The boy could blow out the candle." The verb "blow" needs to be in the base form after "could."
Yes, the sentence is grammatically correct.
The sentence should be "What is the time on your watch".
Yes, but whether it means anything is unclear. A sentence may be grammatically correct and total gibberish at the same time.
"He could not have been there" is the correct sentence. It conveys the idea that he was unable to have been at the specified place.
Yes but you could make it much better. Search for advice on sentence and word structures.
Depending on the sentence, not unless could be the correct form.
The verb in the given sentence, "could be" is in a conditional present tense.
Him and I have a report to do.
rule that could explain what makes a sentence grammatically correct or not before the noun."
No, the correct sentence would be: "Is the sculpture free form?"
No, the sentence is not grammatically correct. A more correct version could be: "Why was she promoted?" or "She was promoted, but why?"
No, the sentence is not correct. It should be "The boy could blow out the candle." The verb "blow" needs to be in the base form after "could."
This sentence is grammatically correct.