Here's why:
* Conjunctions typically connect words, phrases, or clauses. They are not standalone sentence starters.
* However, there are exceptions:
* When the sentence is a continuation of a previous thought, a conjunction can start the sentence. This is called a "comma splice", and while technically grammatically incorrect, it's often used in informal writing to create a sense of flow. For example:
* "I love to bake. And my favorite thing to make is cookies."
* Sometimes conjunctions can start a sentence in a "sentence fragment". This is often used for stylistic effect, emphasizing a particular part of the sentence. For example:
* "But a new problem arose."
* In some cases, a conjunction might be used as part of a complex sentence structure, where it's essential for connecting clauses. However, even in these cases, the conjunction wouldn't technically be the "first word" of the sentence in the traditional sense. For example:
* "Although she was tired, she still went for a walk."
It's generally best to avoid starting a sentence with a conjunction unless you have a clear reason for doing so. It's important to be aware of the rules of grammar and punctuation, as well as the desired effect of your writing.