RiotNrrd:Also, I notice sometimes people use voli when they really mean deziri; they aren't quite synonyms, although they occupy the same general concept space. I'm just tossing that out there in the ring, though - it's not meant as a criticism. More just a related observation.

Per the Vortaro, I've been interpreting voli as want - I want this, I want that - and deziri as desire - a stronger want.

i.e.
Mi volas kukon - I want cake
Mi deziras kukon - I desire cake (I really want cake)

I think the problem arises from the fact that in English the form of the participle often looks the same as the form of the past tense verb, e. g. "wanted" as in "I wanted to say" versus "wanted" in "wanted dead or alive". But it just looks the same, it isn't the same thing, grammatically. One you translate as "volis" and the other as "volinta" resp. "volita/volata". Many languages, including Esperanto, have different forms for these two different things, so as a native English speaker you have to get used to it and not translate word for word, but the meaning of the sentence. Once you know how to do it in Esperanto, you'll have a better understanding for English grammar as well.

Examples:
- I read a book. (/ri:d/, present tense) = Mi legas libron.
- I read a book. (/red/, past tense) = Mi legis libron.
- I have read a book. (perfect tense) = Mi legis libron.

You could also say "Mi estis leganta libron" = "I was/have been reading a book" to emphasize the length of time or "Mi estas leginta libron" = "I have read a book" to emphasize that you have finished it, but then it is more Esperanto to say "Mi legis libron la tutan posttagmezon" or "Mi finlegis libron.")

- The book is read. = La libro estas legita.
- The book is being read. = La libro estas legata.

*Mi leg(a/i)nta libron* estas malĝusta. Ĝi tradukiĝas kiel "I reading a book".

pohli:
Examples:
- I read a book. (/ri:d/, present tense) = Mi legas libron.
- I read a book. (/red/, past tense) = Mi legis libron.
- I have read a book. (perfect tense) = Mi legis libron.

"I read a book" sounds very unnatural to me for present tense. (English is my first language)
It would only sound natural to very specific questions, esp. hypothetical questions, such as, "what do you like to do when you're bored?" "I read a book" could work, but, even then, simply "I read" would sound more natural to me.

captainzhang:

pohli:
Examples:
- I read a book. (/ri:d/, present tense) = Mi legas libron.
- I read a book. (/red/, past tense) = Mi legis libron.
- I have read a book. (perfect tense) = Mi legis libron.

"I read a book" sounds very unnatural to me for present tense. (English is my first language)
It would only sound natural to very specific questions, esp. hypothetical questions, such as, "what do you like to do when you're bored?" "I read a book" could work, but, even then, simply "I read" would sound more natural to me.

To me as a native English speaker, "I read books" is a perfectly natural response to the question "what do you like to do when you're bored?" to distinguish between reading books and reading other things like magazines or newspapers. I interpret "I read a book" as meaning the person usually reads one particular book.

There are the cases of irrgular verbs where simple past and past participle are different (e.g. went - gone), where also for English-only speakers the difference should become clear:

Mi estis malsana: I was ill.
*Mi estinta malsana: *I been ill.

I thought I would also mention the contracted compound tenses, such as "Mi volintis diri" for "I had wished to say", which is a contracted form of "Mi estis volinta diri". I think this fits better than "Mi volintas (estas volinta) diri", which is more like "I have wished to say". But I also agree that in this case "Mi volis diri" is the most correct form, because as pohli said, this is what you are grammatically saying in English (The "wanted" is not a participle, but the past tense form of want).

Here's a link to Wikipedia's Esperanto grammar section on the compound tenses and their contracted forms.

I personally prefer the contracted forms, but they differ from how most languages seem to do it. Examples such as "Mi kaptintus" -> "I would have caught" are quite concise, yet they are still very clear. The conditional participles are also very interesting, "La reĝunto" -> "The would-be king".

kaŝperanto:I personally prefer the contracted forms...

Don't use them unless you absolutely have to (which will be practically never). About the only ones that people will easily understand are devintus and povintus, because those have become more or less just lexical units at this point. Otherwise, the use of contracted forms will either cause people to have to stop and puzzle out what you just said (which isn't really what you want to happen during a conversation), or to just "blip" over it without getting its full intended meaning (which is even worse).

Always go with the simple forms unless you have a really good reason not to, because otherwise you're just making things more complicated than they really have to be.

RiotNrrd:

kaŝperanto:I personally prefer the contracted forms...

Don't use them unless you absolutely have to (which will be practically never). About the only ones that people will easily understand are devintus and povintus, because those have become more or less just lexical units at this point. Otherwise, the use of contracted forms will either cause people to have to stop and puzzle out what you just said (which isn't really what you want to happen during a conversation), or to just "blip" over it without getting its full intended meaning (which is even worse).

Always go with the simple forms unless you have a really good reason not to, because otherwise you're just making things more complicated than they really have to be.

I agree that there is generally no good reason to use them in conversation (and they should be avoided), but I disagree that they are in any way puzzling if one is familiar with their form. At the very least the "X-intus" should correlate to "would have X-ed" for many verbs.
kaptintus - would have caught
kurintus - would have run
volintus - would have wished/wanted
mortintus - would have died
farintus - would have made
ktp.

In fact, the english translations for devintus and povintus are two which don't fit this general mould: "would have ought-ed" and "would have could-ed", which are properly "should have" and "could have" and generally require another verb. I think these forms are a bit easier (at least for engish speakers) than the est_s X-int_ forms, because of our odd use of two different auxiliary verbs (to be, to have) where esperanto uses only one.

I have seen many contracted forms in "La Hobito", although it is a translation from English and it could be stylistic. But there are also several examples in songs I've listened to. With good second-to-last syllable stress and pronunciation, "intus" is fairly easy to hear in speech. I would only expect to see many compound tenses if someone were telling a story, or if they were describing something where the exact state of the action was important (finished, active, about to be done).

kaŝperanto:...but I disagree that they are in any way puzzling if one is familiar with their form.

Well, that's the problem. As a general rule, because the use of these forms is discouraged in Esperantujo in favor of the simpler forms, most Esperantists aren't familiar enough with them to easily be able to translate them without having to pause for a moment to untangle the pieces.

Certainly that would be remedied by some practice. The problem is... almost no one is practicing. The simpler forms usually cover the same bases (possibly at the expense of a tiny dollop of meaning, but typically that loss isn't very important; where it would be important, there is the need for the more complex forms), so there's no real reason to commit the complex forms to easily accessible memory. So most people don't.

You can certainly go ahead and use these forms. You just won't be as easily understood as if you were using simpler forms (which are almost always sufficient, although certainly exceptions to that can be found).

RiotNrrd:

kaŝperanto:...but I disagree that they are in any way puzzling if one is familiar with their form.

Well, that's the problem. As a general rule, because the use of these forms is discouraged in Esperantujo in favor of the simpler forms, most Esperantists aren't familiar enough with them to easily be able to translate them without having to pause for a moment to untangle the pieces.

Certainly that would be remedied by some practice. The problem is... almost no one is practicing. The simpler forms usually cover the same bases (possibly at the expense of a tiny dollop of meaning, but typically that loss isn't very important; where it would be important, there is the need for the more complex forms), so there's no real reason to commit the complex forms to easily accessible memory. So most people don't.

You can certainly go ahead and use these forms. You just won't be as easily understood as if you were using simpler forms (which are almost always sufficient, although certainly exceptions to that can be found).

I suppose it is more of a catch-22; nobody uses them because nobody studies them enough to catch their meaning easily in conversation. I liken them to such things as "bluas", "paradizas", "junas", and other less-commonly used "verbified" words, since we are just "verbifying" the adjectival participle. I certainly don't think they should be used any more than "will have done", etc. are used in English, which is only used when necessary to say what you mean.

I did notice another interesting correlation between English and Esperanto by means of your examples. "Should have" and "could have" are both commonly contracted as "should've" and "could've", so it is interesting that their contracted forms are more common in Esperanto as well.