What is the use of participles?
I was wondering what was the use of participles (like when the verb ζω becomes ζώντας) as they don't appear to work like adjectives.
The active voice verbs, ending in -ω, have participles that work like gerund does:
Being a doctor, I know the value of life - Όντας γιατρός, ξέρω την αξία της ζωής.
I saw a rainbow (while) returning home - Είδα ένα ουράνιο τόξο γυρίζοντας σπίτι.
Children learn (while/by) playing - Τα παιδιά μαθαίνουν παίζοντας.
These are a few phrases that pop into my mind now, I'm sure you can find better examples around. Obviously you can rephrase some of them to avoid using the participle, e.g. as I was returning / ενώ γυρνούσα, through play/ μέσω του παιχνιδιού, but there are cases where using the participle is best (like the first example).
The Greek passive voice participles that end in -μένος. -μένη, -μένο work like adjectives.
There are also the less used active voice participles that work like adjectives, too, ending in -ων, -ουσα, -ον. Some of them are considered adjectives in modern Greek, but in fact they are participles (and mean "the one who...") Ο Ομιλών=the one who talks, ο τρέχων=the one who runs, ο ενδιαφέρων=the one who interests ie interesting etc
What are their declinaison? are they different from το να or the suffixes -μα and -ιμο?
I think you have confused the infinitive with participles. Το να τρέχεις or το τρέξιμο refer to the act of running. Participles ο τρέχων, η τρέχουσα, το τρέχον refer to the person who runs and are used as adjectives. Το τρέχον έτος=the current/running year, for example. Το τρέξιμο/Το να τρέχεις είναι καλό=(The act of) running is good. The active voice participles declination is that of ενδιαφέρων: Ο ενδιαφέρων/του ενδιαφέροντος/τον ενδιαφέροντα/ οι ενδιαφέροντες/των ενδιαφερόντων/τους ενδιαφέροντες, η ενδιαφέρουσα/της ενδιαφέρουσας/την ενδιαφέρουσα/οι ενδιαφέρουσες/των ενδιαφερουσών/τις ενδιαφέρουσες, το ενδιαφέρον/του ενδιαφέροντος/το ενδιαφέρον/τα ενδιαφέροντα/των ενδιαφερόντων/τα ενδιαφέροντα.
I hope this part of Grammar is not so difficult to understand, even it is an advanced one. If it seems too difficult, just take a look at the examples.
About the participles from the school Grammar of Junior High School: http://ebooks.edu.gr/modules/ebook/show.php/DSGYM-A112/621/4007,17983/
There are 3 types of participles in Modern Greek:
a) The participle of Present of Active Voice (this is what you are asking for) in -οντας or when accented, -ώντας.
b) The participle of Present of Passive Voice ( suffix -μένος, -μένη, -μένο)
c) The participle of Past Perfect of Passive Voice (suffix -μένος, -μένη, -μένο)
About (a): The participle of Present of Active Voice is invariable and denotes an act that is done at the same time as the act that states the verb of the sentence in which the participle is: Έδινε εντολές με τα χέρια μιλώντας ταυτόχρονα στο κινητό. (=He was giving orders with his hands speaking in the same time on his mobile). The participle of Present of Active Voice has always its subject in nominative and it is usually the same as the subject of the verb that identifies (attached participle): Η Ελένη έφυγε τρέχοντας για το σπίτι (=Helen left running to her home). In some rare cases, the subject of the participle may be different from the subject of the verb that determines: Ανεβαίνοντας το βουνό, ο ιδρώτας άρχισε να ρέει ασταμάτητα.(=Climbing the mountain, sweat began to flow incessantly). The participle of Present of Active Voice expresses several adverbial relationships, mainly way, but also time, reason, hypothesis, and opposition (adverbial participle). i.e. Έφυγε περπατώντας βιαστικά (place) (=He left hurriedly walking).
I am not writing anything about (b) and (c) except this:
In these types of participle, it is possible to include the expression forms of periphrastic types of the participle of the Past Perfect of the Active and Passive Voice. They operate in a similar way to the participle of the Present of the Active Voice, but they declare an act prior to the act proclaimed by the verb of the main sentence. i.e. Έχοντας γράψει όλες τις επιστολές, ένιωθε σίγουρος για το μέλλον (=Having written all the letters, he felt confident about the future).
Finally the participle of the Present of Active Voice in -ων, -ουσα, -ον or -ών, -ούσα, -όν/-ούν, of the Past of Active Voice in -ας, -ασα, -αν and the Past of Passive Voice in -είς, -είσα, -έν, that come from Katharevousa and they are used very formally, in theological texts mostly and sometimes by journalists, are adjectives actually: Ο αρχιεπίσκοπος επιβράβευσε τους μελετώντας την Αγία Γραφή (= The Archbishop rewarded those who study the Bible) etc.
I hope it helps :)