It is very smart to check spelling of the text before translation to make sure that it’s error free.
The built-in spellchecker checks spelling for English, French, German, Italian, Portuguese, Russian, Spanish, and Ukrainian languages.
Mark the Auto "Spell" checkbox to run the spellchecker automatically when you click on the Translate button. The spellchecker will check spelling of the original text and provide spelling suggestions.
The auto spell-checking function is synchronized with the selected language pair. ImTranslator automatically picks the spelling language of the source text if this language is supported by the spellchecker. For example, if the translation direction is English-Russian, then the spelling language for the source window is English and for the translation window is Russian.
It is highly advised to check spelling of your text before translation to get better translation results.