About TwinMarker for Firefox addon

Addon Version

TwinMarker is a Free Online Grammar Checker for English language learners. The addon version adds the data import and export features to the generic version. This addon allows you to copy the text from the focused area on a webpage and write it back to the source page. The grammar checking is performed on the server-side(http://twinmarker.net/).

Download TwinMarker for Firefox

Spell Check

Unknown(or spelling error) words and proper nouns are highlighted in green.

Grammar Check

Grammatical error words are highlighted in red. TwinMarker typically checks the following errors:

The Agreement of Subjects and Verbs: checks for the third person singular present form of verbs.

Determiner Usage: checks for redundant determiners, the order of determiners, and the combination of determiners and nouns.

The Combination of Verbs and Objects:

The Other Word Usage:

TwinMarker v1.8 Document Page
Grammar Checker Top