The first part of this post may be attributed to the Latin language itself. The second is in large part due to the genius of Vergil and his genius with verse You may make of both of them what you will. :-)
The Latin participle is, in general, more compact than its English equivalent. There are four kinds of participles in Latin: the present active, future active, perfect passive, and future passive. Latin is somewhat unique in possessing no perfect active participle (except for deponent verbs--if you don't know what those are, don't panic). The perfect passive participle generally filled the breach on this point, and the student is usually expected to supply an active translation while implicitly understanding that, technically, the grammatical sense is passive.
The Latin participle is, in general, more compact than its English equivalent. There are four kinds of participles in Latin: the present active, future active, perfect passive, and future passive. Latin is somewhat unique in possessing no perfect active participle (except for deponent verbs--if you don't know what those are, don't panic). The perfect passive participle generally filled the breach on this point, and the student is usually expected to supply an active translation while implicitly understanding that, technically, the grammatical sense is passive.
Generally, except for the ability to place it far and away from the noun it modifies as discussed in my first post, the present active participle does not differ much from English (except that it is declined like an adjective). In English we use a verb ending in -ing, for example, running; in Latin one would stick an -ns suffix to the verb currere, to run, to obtain the present active participle currens.
Moving into the future active participle, the compactness begins to reveal itself. The closest English approximation we have to the future active participle is something like about to (verb). Latin takes care of it by simply attaching urus, -a, -um to the 4th principle part of a verb. So when we would say, "Aeneas, about to run to Italy, was very happy," the Romans would say "Aeneas, ad Italiam cursurus, erat laetior." Latin can shave three words off English and, I daresay, sound rather more polished than the former. But that is for the second part.
The perfect passive participle is probably the participial form one will encounter the most often, at least in the Aeneid. As far as I have encountered, the most literal English translation of this participle (I'll use a different verb for convenience, say, to kill) would be having been killed--rather clunky in some circumstances. In English we might say "the man, having been killed, fell to the ground." In Latin one would say "vir, necatus, ad solum occidit." Nine versus five!
As to the future passive participle, more commonly known as the gerundive, I confess that that is one grammatical area in which scraping off a little rust would do me good. I shall have to consult my faithful Alan and Greenough's on the subject. My main haziness, I think, is on the distinction between the gerundive and gerund (the former an adjective and the latter a verbal noun) and on the situations in which one or the other is used. The general sense of the gerundive is something like about to be killed (sorry, that's just a common word in Latin!). So, "the bull, about to be killed at the altar, bellowed" is roughly equivalent to, "taurus, necaturus ad altam, fremit."
Before we leave the subject of participles, which I hope was not boring (it may indeed be informative to any students trying to master participles, I suppose, and I hope it is), I ought to consider a few of the other applications of participles. One of the funnest is known as the ablative absolute, which can (but does not always) use a participle. This nifty little construction consists of two words, either a noun and a verb, or a noun and another noun or adjective, with an implied to-be verb in the mix. Both of the words are in the ablative case, which is a little hard to explain to those who have never learned Latin. It's kind of a grab-bag noun case that many prepositions take and which often expresses other concepts of direction, characteristics, means, and so on. A good example of the ablative absolute would be urbe capto. This versatile phrase can mean several things, depending on the context. It could mean "since the city was captured," "when the city was captured," "the city being captured," and other things as well.
Vergil's verse is considered by many scholars to be one of the most masterful examples of dactylic hexameter in Latin. Dactylic hexameter is a verse form consisting of six feet, or sections of syllables. These may comprise either dactyls or spondees. Dactyls are one long syllable followed by two short ones, and spondees are two long syllables. Since I do not have the know-how to create any fancy symbols, I will represent long syllables by putting them in all capital letters. Note first that these do not necessarily represent the stress on a particular syllable, i.e., how loud one pronounces it, but just how long the vowel-sound is held.
The rules of scanning dactylic hexameter appear complex on the surface, but, once mastered, are not very difficult to remember or employ. Essentially, as a starting-point, one would cram all the lines of a hexameter line together (as, one might add, the Aeneid was originally written, as were all works of ancient times). Let's take the first line:
arma virumque cano, Troiae qui primus ab oris
Now let's scrunch it together:
armavirumquecanotroiaequiprimusaboris
Now. The first rule of scanning hexameter is to divide the line by syllables. One always breaks off after the vowel and before the consonant, unless there are two consonants together, in the which case one retains one consonant and starts with the next. Like so:
ar ma vi rum que ca no troi ae qui pri mu sa bo ris
Now what? Well, we know there have to be six feet in this line; that's what "hexameter" means. We know that each of these feet can be either a dactyl or a spondee. There's a nifty thing we can use, too, to get us started: the last two feet of every line, called the Adonic Section, always takes a specific form--one dactyl plus two feet that are either a spondee, or one long and one short syllable (kind of a truncated dactyl). As for the rest of the line, any vowel that has a consonant at the end is long "by position." Some other vowels are long "by nature," and one just has to feel those. Unless proven otherwise, vowels with no consonant after them are short.
Yes, you may be staring around bewildered now. I was too when I first learned this. I'll give you an example of the first line, scanned:
AR ma vi RUM que ca NO TROI AE QUI PRI mu sa BO RIS
See how that works? For starters, "ar," "rum," "troi," "ae," "qui," and "ris" are all long by position (diphthongs count too). Remember, they all have consonants at the end or are diphthongs. The reason I knew that "no" and "pri" were long by nature is because of how the line was going. One can have no more than two long or two short syllables in a row. Once "que ca" had been proven short, "no" couldn't be anything other than long.
There are a few other rules, but I think I have said quite enough now. I hope anyone who reads these posts can take something from them. It is good to be able to write out some of what I've learned here, and communicate the excellent qualities of the Latin language. My next post, and probably my last on this subject for now, will be on the beauty of Vergil's Latin, and how he positions words and uses multiple figures of speech to achieve some pretty amazing effects.