Punctuation Differences for Non-Native English Writers

Grammar gets the attention, but punctuation is where your first language quietly leaks through. You can write a flawless English sentence and still mark yourself as non-native with a single comma in the wrong place, a space before a colon, or a quotation mark borrowed from your keyboard's default layout. Readers rarely know why a paragraph feels slightly off — but they feel it.

The good news: punctuation rules are finite and mechanical. Unlike article usage or phrasal verbs, you can learn the full set and apply it every time. This guide walks through the punctuation habits that most reliably betray a non-native writer, names the first languages they come from, and gives you a clean Wrong / Right for each.

Quotation marks: your keyboard is lying to you

Almost every language marks quoted speech differently, and the default key on your keyboard often inserts the wrong one for English. Russian and French use guillemets (« »). German uses low-high marks („ "). Japanese uses corner brackets (「 」). English uses curly double quotes for the outer layer and curly single quotes inside.

Wrong: She said «I will be late» and hung up.

Wrong: She said „I will be late" and hung up.

Right: She said, "I'll be late," and hung up.

For a quote inside a quote, English nests single marks inside double:

Right: "Did she really say 'I'll be late' again?" he asked.

There is a second, subtler trap: straight quotes versus curly quotes. A straight quote (" or ') is the typewriter character your editor inserts before autocorrect fixes it. Curly (or "smart") quotes (" " and ' ') are what published English uses. Mixing them in one document is a classic sign that text was pasted from several sources.

Wrong: The "report" is "ready".

Right: The "report" is "ready."

One more American-English rule that surprises almost everyone: periods and commas go inside the closing quotation mark, even when they are not part of the quote. (British English often places them outside, so pick one convention and hold it.)

Numbers: the decimal and thousands separators are swapped

This one causes real-world errors, not just stylistic ones. English uses a comma for thousands and a period (point) for decimals. Much of continental Europe — German, Spanish, Italian, French, Russian — does the exact opposite.

Wrong: The device costs 1.299,50 dollars.

Right: The device costs 1,299.50 dollars.

French and several other languages also use a space (or a non-breaking thin space) as the thousands separator: 1 299,50. In English, write 1,299.50. If you are writing about money, dates, percentages, or measurements, this is worth a careful pass — a misplaced separator can change a number by three orders of magnitude. For the full set of number, date and currency conventions, see how to write numbers, dates and times in English.

Spacing before punctuation: the French space

French typography puts a space before "high" punctuation — the colon, semicolon, question mark and exclamation mark. English does not. This is one of the fastest tells, because it shows up in casual writing where everything else might be perfect.

Wrong: Are you ready ? We need to leave now !

Right: Are you ready? We need to leave now!

Wrong: Here is the list : milk, bread, eggs.

Right: Here is the list: milk, bread, eggs.

The rule in English is simple and absolute: no space before a punctuation mark, one space after. The same goes for the comma, period, and the opening of parentheses. (And no — English no longer uses two spaces after a period; one is standard.)

The Oxford (serial) comma

When you list three or more items, English gives you the option of a comma before the final "and" or "or." That last comma is the Oxford, or serial, comma.

Without it: We invited the lawyers, a senator and a judge.

With it: We invited the lawyers, a senator, and a judge.

The Oxford comma is optional, but it removes ambiguity — without it, the sentence above can read as if the senator and judge are the lawyers. Most US academic and business style guides recommend it. The real rule is consistency: choose one approach and apply it to every list in the document.

Comma splices: the most common structural tell

A comma splice joins two complete sentences with only a comma. Many languages — Spanish, Russian, Greek, Italian — allow exactly this, so the habit transfers directly into English, where it is an error.

Wrong: The meeting ran long, we missed the train.

You have three clean fixes:

Right (period): The meeting ran long. We missed the train.

Right (semicolon): The meeting ran long; we missed the train.

Right (joining word): The meeting ran long, so we missed the train.

The semicolon deserves a note of its own: in English it joins two closely related complete sentences, or separates items in a list that already contains commas. It is not a heavier comma, and it does not go before "and."

Em dash, en dash, and hyphen are three different marks

English uses three horizontal marks of different lengths, each with its own job. Most languages collapse them into one, which is why non-native writers tend to use a single hyphen everywhere.

• Hyphen (-) joins words: well-known, twenty-three, state-of-the-art.
• En dash (–) spans ranges: pages 10–20, 2020–2024, Monday–Friday.
• Em dash (—) sets off an aside — like this — or marks a sharp break in thought.

Wrong: The report covers 2020-2024 - it is long.

Right: The report covers 2020–2024 — it is long.

If your keyboard makes the em dash hard to type, two hyphens (--) is a widely accepted stand-in that most editors auto-convert. Whatever you choose, be consistent: do not mix a real em dash in one paragraph and a hyphen-as-dash in the next.

Capitalization: days, months, languages, nationalities

English capitalizes far more than most languages. Days of the week, months, languages, nationalities, and adjectives derived from proper nouns are all capitalized — even mid-sentence. Spanish, French, Italian and Russian all write these in lowercase, so this is a very visible, very frequent tell.

Wrong: On monday she practices her english and spanish with a french tutor.

Right: On Monday she practices her English and Spanish with a French tutor.

The same applies to nationalities and the languages themselves: a Japanese novel, the German market, an American accent. If it comes from the name of a country, people, or language, it gets a capital letter in English.

The ellipsis

The ellipsis is three dots that mark an omission or a trailing-off thought. English uses exactly three — not two, not five, and not a string of dots used as casual punctuation the way it appears in some informal Russian and East Asian writing.

Wrong: I was going to call you....but then I forgot.

Right: I was going to call you … but then I forgot.

In formal writing, the ellipsis takes a space on each side (or follows your style guide's rule), and there is a single dedicated character (…) rather than three separate periods. Use it sparingly — overusing it reads as hesitant or melodramatic in English prose.

Quick reference: your language might do X, English does Y

A faster way to catch these

You will not internalize every rule at once, and you should not have to. The fastest workflow is to draft freely, then run a cleanup pass before you hit send. A free Text Cleaner will normalize straight versus curly quotes, fix stray spaces before punctuation, and standardize dashes in seconds — exactly the mechanical errors that are hardest to spot in your own writing.

For the deeper structural issues — comma splices, capitalization, missing serial commas — the Diglot grammar checker flags them in context and explains why each one is wrong, so the rule sticks for next time. Diglot is built for the bilingual workflow specifically: it knows that your habits come from another language and corrects with that in mind, rather than treating you like a careless native speaker.

Punctuation is the quiet layer. Once it stops marking you as non-native, the only thing readers notice is your ideas — which is exactly the point. If articles are the next habit you want to fix, read our guide to articles (a, an, the) for article-less languages.

Write in your language. Punctuate like a native. Try the Diglot grammar checker free.