I find it amusing that most people who write articles against passive voice use passive voice in those very articles, but the history I learnt from #MastoDaoine showed me a completely different perspective on the whole thing.
In some languages, there’s are so-called deponent verbs — verbs whose forms look grammatically passive but have active meanings. They are pretty common in Latin, but in Old Irish passive forms were apparently so widely used that they completely supplanted former active forms for many verbs.
Here’s how a normal, non-deponent verb can work:
“Crenaid ind notaire libru” — “The scribe(ind notaire — nom.sg.) buys (crenaid — verb, present, 3sg, active) books (libru < lebor — acc.pl.). Old Irish allow omitting the subject because it has unique verb forms for every person and number, so one can also say “crenaid libru” — “an unspecified person, she or he, buys books”.
“Crenar libair lasin notaire” — “Books(libair — nom.pl.) are-bought (crenar — verb, present, 3sg, passive) by-the (lasin — prep+def.art) scribe (notaire — acc.sg.)”. The ‘r’ ending is a sign of a passive form.
Now let's consider this sentence:
“Ro-cluinethar ind notaire inna bríathra”. There’s an ‘r’ at the end of ‘ro-cluinethar’, which implies that it’s in passive voice and originally it would mean “the words are heard by the scribe”. In reality, it’s “The scribe(ind notaire — nom.sg.) hears(ro-cluinethar) the words(inna bríathra — acc.pl.)”. “Ro-cluinethar inna bríathra” means “she or he hears the words”, not “the words are heard”.
But Old Irish people certainly loved their passive voice and quite a few of those deponent verbs developed new, "twice-passive" endings. “Ro-cluinter inna bríathra lasin notaire” — “The words are heard by the scribe”. Some verbs do not have special twice-passive endings or they are not attested in manuscripts, so “labraithir ind notaire inna bríathra” may mean “the scribe speaks the words” or “the words are spoken by the scribe”. In a sense, both mean the same thing so there's no ambiguity there...
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So, what happened to the Old Irish passive verb forms?
The verb system changed dramatically between Old Irish and Modern Irish, and one of the effects is that there is no passive voice in Modern Irish anymore.
The old ‘r’ endings came be to be used for impersonal (“autonomous”) verb forms that cannot take subjects.
“Ná caitear tobac anso” is a frequently-seen “no smoking” warning.
It cannot really be translated as “tobacco is not used here” because you cannot add “by anyone” or similar to that sentence without changing the verb form.
It’s more like “one does not use tobacco here” — but without the placeholder subject.
The lack of passive voice doesn’t mean that one cannot syntactically emphasize the object in Modern Irish. But instead of a different verb voice, that can be expressed with a special particle (“á”) and a verbal noun: “tá an leabhar á dhíol” is, semantically, “the book is being sold”, but literally more like “the book(an leabhar — nom.sg.) is(tá) in-its-sale”.
The language lost its passive voice and re-developed a passive construction after it. Long before anyone was writing articles against passive voice.
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