A novel in English as a non-native writer
The English-language fiction market is many times the size of almost any other, and most writers outside it quietly assume the door is shut. It is not, and the reason is narrower than "AI can translate now".
Writing a novel in English requires that you can judge English. It does not require that you can produce it at speed. Those are different abilities, and only one of them can be handed to a machine.
The ability you actually need
You need to read English well enough to know when a sentence is wrong. Not to write it, not to write it quickly, not to have an ear for every register — to recognise, in a line in front of you, that a character would not say that.
That is a much lower bar than writing, and a real one. If you cannot tell a good English sentence from a merely grammatical one, you cannot ship a book in English, and no tool changes that. It is the honest requirement, and anyone who tells you otherwise is selling.
Set the project to English, not yourself
The language belongs to the book, not to the conversation. Set the project to English and the prose comes out in English — while you can keep thinking, planning and arguing with the tool in your own language, which is where you are fastest and most precise.
This split matters more than it sounds. Planning in a second language quietly flattens your ideas: you pick the plot turn you can express, not the one you want. Keep the thinking in the language you dream in and the output in the language you publish in.
What the machine is good at here
Fluency and idiom at the sentence level — exactly where a non-native draft usually gives itself away. Prepositions, article use, the rhythm of a line of dialogue, the small collocations nobody can list but every reader feels.
It is not making you sound like a native by magic, and it is worth being precise about that: what it does is write English prose from your direction. The register you get is the register you steer for, and judging whether it landed is your job, every paragraph.
Where non-native reading fails hardest
Dialogue and idiom. Read those twice. Description you can usually judge; a line of speech that is subtly too formal, a slang usage that is ten years stale, a joke that does not work — those slip past a reader who learned the language in books.
Names, honorifics and register between characters are the other trap: how two English speakers of different classes, ages or regions address each other carries information, and getting it flatly uniform is the most common tell in a translated-feeling novel.
What this is not
It is not a way to publish in a language you cannot read. If you need the book to exist in English but cannot verify it, what you have is an unchecked manuscript with your name on it, and that is a worse position than not shipping.
And it is not a lesser book. Writing in an acquired language is an old and respectable tradition — Conrad, Nabokov, Ishiguro’s narrators. The idea is yours, the structure is yours, the judgement at every line is yours. The language is a medium you are working in, not a disguise.
Common questions
Can I write a novel in English if English is not my first language?
Yes, provided you can read English well enough to tell a good sentence from a merely correct one. Producing fluent English prose can be handed over; judging it cannot. Set the project to English, keep planning in your own language, and read every paragraph before you keep it.
Will readers be able to tell it was not written by a native speaker?
It depends almost entirely on dialogue. Narration composed with help usually passes; speech is where a non-native ear misses — a line a character would never phrase that way, slang a decade out of date, a uniform register between people who would not share one. Read the dialogue twice, out loud if you can.