Yes, you can start a sentence with however.

The core rule

When however means “but” or “nevertheless,” you can put it at the very beginning of a new sentence and follow it with a comma.

It was raining. However, we still went to the beach.

That use is standard in modern English, including formal writing like academic or legal texts.

Why some teachers said “don’t”

Older style guides (and some teachers) warned against starting sentences with however when it means “nevertheless.” Their worry was that writers would punctuate it badly and confuse readers.

Because of that, people were told to move it into the middle of the sentence instead:

It was raining. We, however, still went to the beach.

Modern grammar and writing guides now openly accept sentence-initial however as correct, as long as the punctuation is handled properly.

Punctuation: the real issue

There are two common meanings, and the punctuation changes slightly.

  1. Meaning “but / nevertheless” (contrast between sentences)
    • Put however at the start.
    • Follow it with a comma.
    • Make sure what follows is a complete sentence.

Examples:

 * I love chocolate cake. However, it isn’t good for my health.

 * It’s winter. However, today it’s not cold.
  1. Meaning “no matter how / to whatever extent”
    • You can put however at the start, but you do not use a comma right after it.

Examples:

 * However hard Jason tries, he just can’t get his grades up.

 * However fast you run, you won’t arrive before me.

The key is that after however , you still need a full sentence, not just a fragment:

Wrong: However, driving in the middle of the city. (fragment)

Correct: However, driving in the middle of the city was a little bit stressful.

Style and formality tips

Many professional editors and style resources say that starting with however is not only acceptable but often clearer, because it signals contrast upfront.

Some conservative readers (for example, in certain business or job-application contexts) still dislike it, so a few guides suggest avoiding sentence-initial however in ultra-formal documents like cover letters, just to be safe.

If you want to avoid starting a sentence with however , you can:

  • Use a semicolon + however inside the sentence:
    • It was raining; however, we still went to the beach.
  • Or simply use but :
    • It was raining, but we still went to the beach.

Mini FAQ

Q: So is “However, I don’t agree” correct?
Yes. It’s a complete sentence after however , and the comma is correct when it means “but / nevertheless.”

Q: Is there ever a hard rule against it now?
Modern guides do not ban starting a sentence with however ; they focus on avoiding run-on sentences and fragments, and on using the right comma or semicolon.

TL;DR: You can absolutely start a sentence with however; just follow it with a comma when it means “but,” make sure the rest of the sentence is complete, and be aware that a few old-school readers still prefer more traditional alternatives in very formal contexts.

Information gathered from public forums or data available on the internet and portrayed here.