Let's spend some time this week on parts of speech. This post is on the adverb. The fun is in getting them right, and, if your personality is such, helping others with their adverbs.
An adverb is a word used to modify a verb, an adjective, or another adverb. An adverb can also modify an entire sentence, as in Regrettably, my opponent won the slalom competition.
Almost all words that end in ly are adverbs (quickly, largely), but some are not (friendly and leisurely are adjectives, though the latter is correct, if awkward, as an adverb too). Many common adverbs do not end in ly (very, quite), and some of these are adjectives as well as adverbs (better, long) and may require a hyphen joining them to the word they modify to prevent misreading. Often a word that is usually a preposition becomes an adverb, as in Used-car buyers like to trade up, in which up modifies the verb trade rather than acting as a preposition.
Adverbs are often misused as adjectives, as in I feel badly. Adverbs are also often used when adjectival forms might be better, e.g. first...second vs. firstly...secondly.
Adverbial phrases and adverbial clauses are so called not because they contain adverbs—often they do not—but because they function as adverbs. He swore when shaving and sang while he showered contains the adverbial phrase when shaving, modifying swore, and the adverbial phrase while he showered, modifying sang. Since swore and sang are verbs, the modifying phrase and clause are considered adverbial.
A conjunctive adverb is one used to join clauses or to connect the thought of a sentence to the preceding sentence. In She made the first three buoys; however, she crashed before the end of the course, the adverb however is conjunctive. In However, she didn't win the tournament, the adverb However connects the thought of the sentence to that of some preceding sentence and thus is conjunctive. It is also a sentence modifier.
Now - go have fun writing your own adverbial phrases!