Grammar mistakes are underlined with a green wave line and spelling errors with a red one. To correct mistakes you just need to select a word from the Suggestions list. The Thesaurus tab is used for synonyms. The words with found synonyms are marked blue. To change the active word to one of the suggested synonyms you just need to select one of the suggested alternatives in the Synonyms list, and then click Change to. Press Finish Checking and corrected text will be returned to input field.