Spell Check - highlight misspelled words only?

I read in the instructions that spell check can be used to highlight misspelled words only.

I want to use this function because my HTML documents contain a lot of HTML code (like &) and French words, which confuses the spell checker. If I try to check the document word-by-word it is impossible.

I would just like to have words that may be misspelled underlined so that I can quickly see if any of my English words is wrong.

In Spell check options there is the choice to choose the style of the words underlining, but the underlining doesn't appear.

I can't figure out ow to get the spell check to do this.

Any help greatly appreciated!

Regards - David