Sentence examples for a that from inspiring English sources

"a that" is not correct and is not commonly used in written English.
It is possible that someone might say "a that" in spoken English as a shortened form of "all of that," but it would be considered nonstandard or informal. It should not be used in formal or written communication. Example: I can't believe a that happened last night! (incorrect) Example: I can't believe all of that happened last night! (correct).