L1-aware grammar

AI Grammar Checker for ESL & Non-Native English Writers

Diglot is purpose-built for ESL and non-native English writers. It catches the L1-specific patterns generic checkers miss — missing articles, copula drops, false cognates, and translated-sentence rhythm — while you draft, so you ship clean English without copy-pasting between Grammarly, LanguageTool, and your translator.

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*No credit card required

Inside Diglot
One connected editing flow

Generic grammar checkers were trained on native-English writing, so they flag awkwardness but rarely explain why a non-native sentence reads wrong. Diglot is calibrated against L1-transfer patterns — missing articles in Methods sections, copula drops in academic English, false cognates from Spanish or French, and topic-comment word order from Korean and Japanese.

  • Catch L1-specific patterns — article omissions, copula drops, tense shifts, false cognates
  • Get corrections explained with the native-language reason, not just a generic "this is wrong"
  • Run grammar, paraphrase, and translation in the same document — no copy-pasting between tools
Draft, refine, and deliver English in one calm workspace.
Diglot AI grammar checker interface showing L1-aware corrections

What makes a grammar checker built for ESL writers different

Generic grammar checkers were trained on native-English writing, so they flag awkwardness but rarely explain why a non-native sentence reads wrong. Diglot is calibrated against L1-transfer patterns — missing articles in Methods sections, copula drops in academic English, false cognates from Spanish or French, and topic-comment word order from Korean and Japanese.

L1-aware, not one-size-fits-all

Korean writers get article-omission corrections explained against Korean grammar; Spanish writers get false-cognate alerts against their L1. Each fix carries the native-language reason — so revisions compound across drafts instead of starting from scratch every paper.

Calibrated for ESL writing patterns

Detection thresholds are tuned per L1 — stricter article-checking for Korean, Japanese, Chinese, Russian (languages without articles); collocation-aware for Spanish and Portuguese false cognates; word-order checks for Arabic and German.

One workspace, full bilingual workflow

Grammar fix, paraphrase, translation, and originality verification share the same document context. Generic checkers force you between tabs — Diglot keeps your bilingual draft anchored in view while you polish.

How this workflow works

Move from bilingual rough ideas to polished English in one calm flow instead of stitching together separate tools.

Inside this workflow

What you can do with Diglot

Use this workflow to move from bilingual drafts to cleaner English output without breaking your editing flow across separate tools.

What this module includes

The module is not just one button. It is a focused part of the Diglot workspace with real writing actions, review controls, and context-aware output.

Who this is built for

Diglot works best when English is your output language but not always your thinking language.

Editorial review

Why trust this workflow

This page is written for non-native English speakers and reviewed against the current Diglot workflow, not against a generic AI copy template.

Workflow fit

Built around real bilingual writing tasks

The guidance on this page reflects how Diglot handles drafting, translation, grammar review, paraphrasing, and originality checks inside one editor.

Audience fit

Written for people who think in one language and deliver in English

Examples, copy, and workflow steps are shaped for students, professionals, and creators who need clearer English output without losing meaning.

Editorial review

Reviewed by Diglot Editorial Team

Last reviewed on April 11, 2026. We update these landing pages when the workflow, module behavior, or recommended writing path changes.

Frequently asked questions

Everything you need to know before getting started.

Yes — Diglot has a free plan with core grammar checking, paraphrasing, and translation in one editor. Free includes L1-aware corrections for the top six L1s (Korean, Chinese, Japanese, Arabic, Spanish, Russian). Spark ($19/month) and Pro ($29/month) unlock higher word quotas, larger document sizes, and premium model tiers for more accurate corrections.

Yes — grammar, spelling, punctuation, capitalization, sentence clarity, and tone all check inside one pass. Unlike split tools where you have to switch between a spell checker and a separate grammar checker, Diglot surfaces every error category in the same inline review — and explains corrections in plain language, including the L1 reason when relevant.

Yes — Diglot is built for non-native English speakers writing in English. The checker recognizes patterns generic tools treat as random "errors": article omissions from Korean, Japanese, Chinese, and Russian L1s; preposition errors from Spanish, German, and French; tense-marker drops from Mandarin; topic-comment word order from Korean and Japanese. Each fix is explained in your L1 context.

Yes — Diglot works best as you draft, not as a post-write proofreading layer. Corrections surface inline as you type, the paraphraser sits next to your cursor, and the translator anchors your L1 source on screen the whole time. This means you fix patterns as they appear instead of accumulating them across an 8,000-word draft you then have to rebuild paragraph-by-paragraph.

Yes — that is the point. Diglot maintains an L1-transfer-pattern database for each supported language: Korean -고/-며 connector chains producing English comma splices, Japanese topic markers becoming awkward English subjects, Chinese aspect markers (le, guo, zhe) mapping to wrong English tenses, Arabic definite-article overuse, Spanish subjunctive overcorrection. Generic checkers treat each as a one-off — Diglot recognizes the pattern.

Yes — all four core tools (grammar checker, paraphraser, AI translator, originality verifier) share the same document context inside Diglot. Translate a paragraph from Korean or Spanish, run a grammar pass on the English result, then paraphrase any awkward sentences without losing the surrounding draft. Generic stacks force four browser tabs and four copy-pastes — Diglot keeps it in one editor.

Grammar Checker for speakers of:

Diglot's checker models L1-to-English transfer patterns for each language family. Pick yours for the patterns we specifically address.

Write in your language,
publish in English

Move from rough bilingual drafts to clearer English in one connected writing workflow.

Start for free

*No credit card required

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