Sentence examples for a corn from inspiring English sources

The phrase "a corn" is not grammatically correct or commonly used in written English.
It is possible that "a corn" could be used in spoken language as a shortened or slang version of "a corn plant," but even in this context it would not be considered standard usage. It is always best to use proper grammar and complete sentences in written English. Incorrect: I went to the farm and saw a corn. Correct: I went to the farm and saw a field of corn.