Yes. Starting a sentence with “but” is correct English, it always has been, and no rule of grammar forbids it.
If a teacher told you otherwise, they were passing on a classroom habit, not a rule of the language.
Where the myth came from
Nobody sat down and banned it. What happened is more ordinary.
Young writers, given no guidance, produce this:
I went to the shop. But it was closed. But I needed milk. But there was another shop. But it was far.
That is genuinely bad writing. So teachers told children to stop starting sentences with “but”, as a temporary correction for a real problem.
The instruction worked. Then it got repeated without the reason attached, and a piece of classroom scaffolding turned into a rule people carry into adulthood.
Style guides do not support the ban. Writers have started sentences with conjunctions for as long as English has been written, and it appears throughout the King James Bible, Shakespeare and modern published prose.
When starting with “but” works well
It is not just permitted. Sometimes it is the better choice.
To give a contrast its own weight
The plan was clever, well funded and popular. But it failed.
Put that in one sentence and the failure gets buried in a list. On its own, it lands.
To break up a long sentence
Although we had prepared for months and everyone had rehearsed their part carefully, the equipment failed on the night.
Split it:
We had prepared for months. Everyone had rehearsed. But the equipment failed on the night.
Three short sentences, easier to read, same meaning.
To sound like a person
Formal writing that never begins a sentence with “but” or “and” reads stiffly. In an email, an article or a blog post, it is what makes prose sound like speech.
When to avoid it
- When the two ideas are short and closely linked. “It was cold. But we went anyway.” is choppier than “It was cold, but we went anyway.”
- When you have already done it twice on the same page. The effect comes from contrast. Used constantly, it becomes a tic.
- In the most formal academic writing, where however, nevertheless or yet may fit the register better. Not because “but” is wrong, but because the tone is different.
But, and, so, because
The same myth attaches to all of them, and the answer is the same.
| Word | Can it start a sentence? | Note |
|---|---|---|
| But | Yes | Strongest for contrast |
| And | Yes | Good for building or adding weight |
| So | Yes | Slightly informal |
| Because | Yes, if the sentence is complete | See below |
Because is the one with a genuine catch. This is wrong:
Because it was raining.
That is not a full sentence. Something is missing. But this is fine:
Because it was raining, we stayed inside.
The rule is not about the first word. It is that the sentence has to be complete. That is a SWABI clause doing its normal job.
The comma question
Do not put a comma straight after “but” at the start of a sentence.
- Wrong: But, the plan failed.
- Right: But the plan failed.
A comma only appears if a whole phrase is inserted next.
- Right: But, as everyone expected, the plan failed.
Where to go next
- What is SWABI in grammar?, the conjunctions that behave differently
- English grammar in plain English
- How to write clearly, including sentence length
- Check a sentence
Questions people ask
Is it grammatically correct to start a sentence with but?
Yes. No standard rule of English grammar forbids it, and published writers have done it for centuries.
Why were we taught not to start a sentence with but?
Because young writers overuse it and produce strings of short, choppy sentences. The instruction was a temporary fix that got passed on as a permanent rule.
Should I use but or however at the start of a sentence?
Both are correct. “But” is plainer and more direct. “However” is more formal and needs a comma after it.
Can you start a sentence with because?
Yes, as long as the sentence is complete. “Because it was raining, we stayed inside” is correct. “Because it was raining.” on its own is not.
For how conjunctions function in English, see the overview of English subordinators on Wikipedia.