Could you pass me the sugar please?
How could you do this to me?
He pondered how he could have handled the situation differently.
He thought he could build the wardrobe, but he couldn't.
You cannot end a sentence with I could not. I could not anyhow. Could you? Maybe you could. Maybe someone else could. But I know I could not. Example Sentence: I know I could not.
By adding the appropriate subject-auxiliary inversion, the sentence could be rewritten as an interrogative sentence.
It could be used in any sentence as an adjective. That sentence could be, "I'm quite busty and I fear it would look matronly on me."
Somebody will have to improve on this answer. One similarity between a sentence and a sentence fragment could be a sentence's length. If somebody says, "Who did that?" you could answer, "I did," and that is a sentence... but in a different scenario, that may be considered a sentence fragment. Why? Because if that sentence was all by itself, "I did," would be nonsense. What did "I" do? "I did jump," could then complete it.
Your question is itself a sentence which uses the word "could".
How could you do that to me! That is an exclaiming sentence in literature.
The verb in the given sentence, "could be" is in a conditional present tense.
No, the sentence "all you could do was keep writing" is a complete sentence because it has a subject ("you") and a verb phrase ("could do was keep writing"). It expresses a complete thought on its own.
An example of a sentence with are could be:"We are very happy that you could come to our party."
Yes, it can be a complete sentence. Someone could say to you "You are looking well" and you could reply "As are you.".
Yeah! A definition sentence, but still a sentence.
I could give you a sentence easily. You could also write your own sentences if you tried.