Editing Esperanto grammar (section)

==Participles==
[[Participle]]s are verbal derivatives. In Esperanto, there are six forms:
* three aspects: 
** past (or "perfective"), present (or "progressive"), and future (or "predictive")
for each of:
* two [[Grammatical voice|voices]]:
** [[active voice|active]] (performing an action) and [[passive voice|passive]] (receiving an action)
The participles represent aspect by retaining the vowel of the related verbal tense: '''i''', '''a''', '''o'''. In addition to carrying aspect, participles are the principal means of representing [[Grammatical voice|voice]], with either '''nt''' or '''t''' following the vowel (see next section).

===Adjectival participles===
[[File:Toddler running and falling.jpg|thumb|''Falonta'', ''falanta'' and ''falinta''.]]
The basic principle of the participles may be illustrated with the verb ''fali'' (to fall). Picture a cartoon character running off a cliff and hanging in the air for a moment. As it hangs in the air, it is ''fal'''o'''nta'' (about to fall). As it drops, it is ''fal'''a'''nta'' (falling). After it hits the ground, it is ''fal'''i'''nta'' (fallen).

Active and passive pairs can be illustrated with the transitive verb ''haki'' (to chop). Picture a woodsman approaching a tree with an axe, intending to chop it down. He is ''hak'''ont'''a'' (about to chop) and the tree is ''hak'''ot'''a'' (about to be chopped). While swinging the axe, he is ''hak'''ant'''a'' (chopping) and the tree ''hak'''at'''a'' (being chopped). After the tree has fallen, he is ''hak'''int'''a'' (having chopped) and the tree ''hak'''it'''a'' (chopped).

Adjectival participles agree with nouns in number and case, just as other adjectives do:
:''ili ŝparis la arbojn '''hakotajn''''' (they spared the trees [that were] '''to be chopped down''').

===Compound tense===
[[Compound tense]]s are formed with the [[adjectival participle]]s plus ''esti'' (to be) as the [[auxiliary verb]]. The participle reflects aspect and voice, while the verb carries tense. For example:
* Present [[Continuous aspect|progressive]]: ''mi estas kaptanta'' (I am catching), ''mi estas kaptata'' (I am being caught)
* Present [[perfect (grammar)|perfect]]: ''mi estas kaptinta'' (I have caught), ''mi estas kaptita'' (I have been caught, I am caught)
* Present [[prospective aspect|prospective]]: ''mi estas kaptonta'' (I am going to catch / about to catch), ''mi estas kaptota'' (I am going to be caught / about to be caught)

These are not used as often as their English equivalents. For "I ''am'' go''ing'' to the store", you would normally use the simple present ''mi iras'' ('I go') in Esperanto.

The tense and mood of ''esti'' can be changed in these compound tenses:
:Past perfect: ''mi estis kaptinta'' (I had caught)
:Conditional future: ''mi estus kaptonta'' (I would be about to catch)
:Future present: ''mi estos kaptanta'' (I will be catching).

==== Synthetic forms ====
Although such [[periphrastic]] constructions are familiar to speakers of most European languages, the option of contracting [''esti'' + adjective] into a verb is theoretically possible for adjectival participles:

:Present [[perfect (grammar)|perfect]]: ''mi estas kaptita'' is equivalent to ''mi kaptitas'' (I am caught)
:Past [[perfect (grammar)|perfect]]: ''mi estis kaptinta'' to ''mi kaptintis'' (I had caught)

In practice, only a few of these forms, notably ''-intus'' (conditional past progressive) and ''-atas'' (present passive), have entered the common usage. In general, most are rare for being more difficult to parse than periphrastic constructions.<ref>Bertilo Wennergren, ''Plena Manlibro de Esperanta Gramatiko'', [https://bertilow.com/pmeg/gramatiko/participoj/kunmetitaj_verboformoj/nekutimaj.html Nekutimaj kunmetitaj verboj]</ref>

===Nominal participles===
Participles may be turned into adverbs or nouns by replacing the adjectival suffix ''-a'' with ''-e'' or ''-o.'' This means that, in Esperanto, some nouns may be inflected for tense.

A nominal participle indicates ''one who participates'' in the action specified by the verbal root. For example, ''esperinto'' is a "hoper" (past tense), or ''one who had been hoping.''

===Adverbial participles===
[[Adverbial participle]]s are used for circumstantial participial phrases:
:''Kaptinte la pilkon, li ekkuris golon'' (Having caught the ball, he ran for the goal).

===Conditional and tenseless participles (unofficial)===
Occasionally, the participle paradigm will be extended to include conditional participles, with the vowel ''u (-unt-, -ut-).''<ref>Timothy Reagan (2009) ''Language Matters: Reflections on Educational Linguistics'', p. 167</ref> If, for example, in our tree-chopping example, the woodsman found that the tree had been [[Tree spiking|spiked]] and so couldn't be cut down after all, he would be ''hakunta'' and the tree ''hakuta'' (he, the one "who would chop", and the tree, the one that "would be chopped").

This can also be illustrated with the verb ''prezidi'' (to preside). Just after the recount of the [[U.S. presidential election, 2000|2000 United States presidential election]]:
* then-president [[Bill Clinton]] was still ''prezid'''a'''nto'' (current president) of the United States,
* president-elect [[George W. Bush]] was declared ''prezid'''o'''nto'' (president-to-be),
* the previous president [[George H. W. Bush]] was a ''prezid'''i'''nto'' (former president), and
* the contending candidate [[Al Gore]] was ''prezid'''u'''nto'' (would-be president – that is, if the recount had gone differently).<ref>This example is somewhat artificial, because the customary word for 'president' (of a country) is the tense-neutral word ''prezid'''e'''nto.'' ''Prezid'''a'''nto'' is typically used for the presidents of organizations other than sovereign countries, and ''prezid'''i'''nto'' is used for former presidents in such contexts.</ref>

Tense-neutral words such as ''prezid'''e'''nto'' and ''stud'''ent'''o'' are formally considered distinct nominal roots, not derivatives of the verbs ''prezidi'' and ''studi''.

The suffix ''-enda'', as in ''pagenda'' 'payable, must be paid' from ''pagi'' 'to pay', is similar to a passive participle of the imperative mood.<ref>Wennergren, 2005, ''Plena Manlibro de Esperanta Gramatiko'', §28.1.</ref>