Pages '09 proofreader usually not working

My Pages '09 proofreader and spellcheck usually doesn't work. My system and Pages is in English, but I'm often working in Polish-English translation. I often have both English and Polish in one document. Please help.

I seem to have solved the problem, finally, by choosing text language in the Inspector.

Thanks for letting us know what solved the problem. This will be sure to help someone else in the future.