The suffixes eg and et are quite useful for showing intensity (or lack thereof) of something, anything. But sometimes you want to be more specific about how something is happening, or perhaps when, or where. For this purpose, the gods have invented the adverb.
An adverb is a word that describes the circumstances in which something happens. In English, many (though not all) adverbs end in -ly, and most (though not all) words ending in -ly are adverbs. In Esperanto, many (though not all) adverbs end in e, and all words (at least those that have more than one vowel) ending in e are adverbs.
Consider the following Esperanto root:
fort' = having the power to cause changes; strong. (1)
Suppose that you want to indicate that the rain is falling heavily. Well, perhaps pluvegas will be satisfactory, but you might also want to be able to say
Forte pluvas.
Or you might want to describe the color, physical or psychological, of the rain. Consider
griz' = having any color whose three components in the RGB system are equal; gray.
Grize pluvas.
A couple of other immediately useful colors are
blank' = having the color whose three components in the RGB system are as great as possible; white.
nigr' = having the color whose three components in the RGB system are zero; black.
And let's add two more roots that relate to the weather here:
tempest' = rain and wind together; storm.
nebul' = many tiny droplets of water floating in the air at ground level and obscuring vision; fog.
We can say, descriptively:
Blanke neĝas
Grize nebulis
Nigre tempestos
Now for one of the neatest and niftiest things about Esperanto:
Every root can play any role in a sentence, depending on what ending you give it, as long as that makes sense.
Take the expression grize pluvas, which we used above. What this means, is that it (whatever "it" may be) is raining, and in a gray fashion. But, by simply reversing the endings, you can recreate this sentence to describe the same phenomenon in quite a different way:
Pluve grizas = "It" is gray (more precisely, is acting or behaving gray-ly, giving an impression of grayishness) in a rainy fashion.
Similarly, you might want to say:
Neĝe blankas
Nebule grizis
Tempeste nigros
Question about these two-word sentences: Which word comes first? Do you always have to put the adverb before the verb, as I've done here? Answer: because adverbs fulfill similar roles with very different words and have only one form, they should preferably go immediately before the word the describe. In sentences such as the above, however, where there's no possibility of confusion, feel free to reverse the word-order if you want (Pluvas forte is perfectly legitimate), but keep the general rule in mind for later.
Finally, one more little word, not an adverb or a verb but just one of those useful little words like ĉu, jes and ne, of which there are perhaps a hundred or thereabouts in the language (you will have to learn them all separately): kaj. This little particle (the technical term is conjunction) is used to link parallel words or constructions together into a whole, and corresponds pretty closely to the English "and", closely enough that you can use the two interchangeably. For instance, you can create forms such as
Forte kaj grize pluvas
Forte fulmas kaj tondras
Blanke neĝas kaj grize pluvas
Finally, a few useful roots to use with your weather words:
varm' = having a high temperature; hot
bril' = emits lots of light; shine
laŭt' = making a lot of noise; loud
or' = rare metal found in California; gold
arĝent' = rare metal found in Nevada; silver
Try combining these (as adverbs) with various (appropriate!) weather words that you already know. Try combining them in groups (using kaj). Then try reversing the functions of the words by interchanging the e and the as, is, os endings. See how many combinations you can derive.
(By the way, the other two words in the title come from the roots kuraĝ', meaning "courage" or "bravery", and elegant', meaning "elegant". The expression is one that was widely used to encourage people to speak "forte, kuraĝe kaj elegante" by the late Rev. Andreo Cseh in his direct-method Esperanto courses in prewar Europe. It was Cseh, incidentally, who invented direct-method teaching, a system that is now used for many other languages in the appropriate circumstances.)