By definition, adjectives modify nouns. But more than 30 French adjectives can sometimes modify verbs instead, thus taking on the role and characteristics of adverbs, including the fact that they are invariable.
As you might guess from their name, adverbial pronouns are caught between two worlds: they are pronouns in the sense that they replace nouns, and at the same time they are adverbs representing a place, a quantity, or the object of a proposition. French has two adverbial pronouns: en and y.
An adverb is an invariable word that modifies a verb, an adjective, or another adverb. Adverbs can provide additional information about manner, quantity, frequency, time, or place - they explain when, how, where, how often, or to what degree something is done.
Adverbs of manner express how the action of a verb occurs. In English, the vast majority of adverbs of manner end in -ly, whereas in French, they mostly end in -ment. They are usually created from adjectives.
The regular -er verb aimer is ubiquitous and very useful, but somehow means both "to like" and "to love." In some contexts, this can make a world of difference as you certainly don't want to tell someone you love them when you're just friends, so how can you make it clear how you feel?
The French words bon and bien can be tricky for French students because they both belong to three different parts of speech (adjectives, adverbs, nouns) and have similar meanings. This is a good lesson that will get you well on your way to understanding the difference.
Comparative adverbs are used to compare the relative superiority or inferiority of two or more things. This superior lesson will keep you from getting an inferiority complex. ;-)
Connectives are links: they combine words, phrases, or sentences. Connectives do not constitute a single part of speech, but rather a category of terms including all conjunctions and prepositions as well as certain types of adverbs and pronouns used in this way.