Solução # 1 (recomendado)
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The easiest way is setting the language by pressing ctrl+A (or only the words in that language) then click the language button in the status bar > Mark selected text as and select the correct language
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Solução # 2
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You can use the macro function. Select Developer tab > Record Macro. Choose any name you like and assign it to a button or keyboard shortcut. After that disable spell check/grammar check as normal and select stop recoding in macro group from Developer tab. Record another macro to enable the check again.
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