Comparing using adverbs, (e.g. she wears it more elegantly) is different from comparing actions or things.
Look at these examples:
Note that to compare adverbs (nicely, quickly, slowly ...), you use comparative words as follows:
|more [adverb] than
|plus [adverbe] que|
|less [adverb] than||moins [adverbe] que|
|as [adverb] as||aussi [adverbe] que
With adverbs, you NEVER agree.
You won't say ''Elle marche plus lentemente que moi.''
Whereas in English, you will need to use a subject pronoun after than (... than I (do), you (do), he/she (does)...), in French you will once again use the stress pronoun after que (... que moi, toi, lui/elle, nous, vous, eux/elles). You will also never repeat the verb with (do/am/have) afterwards.
I run faster than you do.
See also other Comparative structures:
Plus... plus..., moins... moins... = the more...the more..., the less...the less... (comparisons with phrases)
Better and better, worse and worse = de mieux en mieux, de pire en pire (comparisons)
De plus en plus and de moins en moins = more and more and less and less (comparisons with adjectives, adverbs, verbs)
De plus en plus de and de moins en moins de = more and more and less and less (comparisons of nouns)
Making comparisons with adjectives: plus... que, aussi... que, moins... que
Making comparisons with nouns: plus de... que, moins de... que, autant de... que
Making comparisons with verbs: plus que, autant que, moins que
And for Superlative forms, see:
Le, la, les plus and le, la, les moins = the most and the least (superlatives of adjectives)
Meilleur, mieux, pire / plus mauvais, plus mal = better, best, worse and worst (irregular comparatives and superlatives)
Le plus and le moins = the most and the least (superlative of adverbs)