Both of the sentences you provided are grammatically correct, but they have slightly different structures:
"We have not second chance."
"We have no second chance."
In everyday English, the second sentence is more commonly used and sounds more natural. Here's an explanation for each sentence:
"We have not second chance." - This sentence is grammatically correct, but it is less commonly used in modern English. The word "not" is placed before "second," indicating the absence of a second chance. However, it is more idiomatic to use "no" instead of "not" in this context.
"We have no second chance." - This sentence is the more standard and commonly used form. "No" is used to indicate the absence or nonexistence of a second chance. It is a more natural and clear way to express the idea that there is no opportunity for a second chance.
In summary, both sentences are grammatically correct, but the second one is preferred for everyday communication.