Comparing using adverbs (she wears it more elegantly) is different from comparing actions or things.
Look at these examples:
Elle marche plus lentement que moi.She walks more slowly than I.
Il parle plus vite que toi. He speaks faster than you.
He speaks more quickly than you.
Je chante aussi bien que ma tante.I sing as well as my aunt.
Sandra s'habille moins élégamment que lui.Sandra dresses less elegantly than he.
Germaine est allée se coucher plus tôt que Simon.Germaine went to bed earlier than Simon.
Note that to compare adverbs (nicely, quickly, slowly ...), you use comparative words as follows:
| English |
French |
more [adverb] than
[adverb]-er than |
plus [adverbe] que |
| less [adverb] than |
moins [adverbe] que |
| as [adverb] as |
aussi [adverbe] que
|
ATTENTION:
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.
Je cours plus vite que tu fais toi.
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)
Forming the superlative of adjectives in complex cases
Sandra s'habille moins élégamment que lui.Sandra dresses less elegantly than he. Elle marche plus lentement que moi.She walks more slowly than I. Je chante aussi bien que ma tante.I sing as well as my aunt. Luc court moins rapidement que FrançoiseLuke runs less quickly than Françoise Il parle plus vite que toi. He speaks faster than you.
He speaks more quickly than you. Germaine est allée se coucher plus tôt que Simon.Germaine went to bed earlier than Simon. 
