Here's why:
* Sentence Structure: A full stop (period) marks the end of a complete sentence. A new sentence should begin with a capital letter.
* Conjunctions: "And" is a coordinating conjunction that joins words, phrases, or clauses of equal grammatical rank. It's typically used within a sentence, not to connect independent sentences.
Examples:
* Incorrect: "The dog barked. And the cat hissed."
* Correct: "The dog barked, and the cat hissed."
* Correct: "The dog barked. The cat hissed."
List Exception:
You can use "and" after a full stop when you are listing items:
* Correct: "I need to buy milk. And eggs. And bread."
Remember: While this is a general rule, there are always exceptions. For example, you might find "and" used after a full stop in informal writing or dialogue. However, for formal writing, it's best to stick to the standard rules.