Spellcheck is enabled in Yandex.Browser for the operating system's default language.
To set the spellcheck language:
An incorrectly typed word is underlined with a wavy red line. You can correct it manually, or right-click and select one of the spellings suggested by the browser.
If a word is typed in a language other than the spellcheck language but you want to check the spelling:
Set the desired language.
To disable or enable spellcheck: