When you buy the English version of Office 2007, you also get the ability to install proofing tools (e.g., hyphenators, spellers, etc.) for Spanish and French, the two "companion" languages for English. That is, "Each language version of the 2007 Office release includes Proofing Tools for a set of companion languages." If you want to find out what companion language tools come with each version of Office, check out the details here:
For example, do you get other tools when you get the Estonian version of Office? You bet! You also get English, German, Russian, and Finnish language tools. Hope this helps.
-- Jay Waltmunson & Thierry Fontenelle (Program Managers)