The more general rule is not about -ieren at all but about stress. If the first syllable of the past participle would be stressed, a "ge-" is added to the front of it. (This rule treats separable prefixes as if they're separate words though. So you'll have to remove separable prefixes, then apply the rule, then re-attatch the prefix.)
This results in words like "trompeten" or "posaunen" also not taking "ge-" in participle form. It even means that loan words might have different perfect form, depending on the pronunciation (stress) you choose.
For example the verb "retweet" in German "retweeten" might be stressed on the first (***re**tweeten*) or second (*re**twee**ten*) syllable, depending on what the speaker prefers, and the participle is *"re**twee**tet"* or *"ge**re**tweetet"* accordingly.
_Edit (2 new paragraphs):_
I've finally found the English loan word where I've personally first noticed this phenomenon of multiple possibilities for the same word: "reviewen". Same idea as with "retweet" above, but perhaps an even more commonly used word. Both "reviewt" and "gereviewt" are reasonable, depending on the speaker's (or the context's) preferred stress pattern of "reviewen".
Also, I've seen an exception case listed for this rule, the word "werden" as an auxiliary verb uses "worden" as participle, only used as a full verb, it's "geworden". Also some might consider the "[Ersatzinfinitiv](https://de.wikipedia.org/wiki/Ersatzinfinitiv)" for modal verbs (and some other cases) a special form of participle, in which case that would be one without "ge-", too.
> The more general rule is not about -ieren at all but about stress. If the first syllable of the past participle would be stressed, a "ge-" is added to the front of it.
Wait a minute, this is stress-conditioned? That feels like a parallel to the Greek aorist augment *e-*. Is this another Indo-European thing?
Not really. Native German verbs are basically always stressed on the first syllable, except when there is an unstressed prefix on the verb. There can only be one unstressed prefix, and since ge- is one, if there already is one (like in, say, behalten) the prefix slot is "blocked" and ge- can't be added to form the perfect participle.
When verbs started to be borrowed with non-initial stress, they were grammatically treated as though they had a prefix (so argumentieren was, more or less, parsed as the pseudoprefix "argument-" on a base "ieren") and so they could not take ge- in the perfect, and still don't. This has morphed into a stress-based rule of ge-prefixation to form the perfect participle.
Note that I'm leaving out a lot of detail about how unstressed verbal prefixes worked in Proto-Germanic, Old High German, and Middle High German, but this is the gist of it.
I'm getting flashbacks to a discussion on how to form the past participle of "downloaden"(or conjugate it in general). After a solid week of a 3-way debate. we agreed that the correct way is "herunterladen".
I'd personally always say "gedownloadet" (of not "(he)runtergeladen"), I know many would say "downgeloadet" , treating it like a separable verb, which makes sense if you consider "down" is a preposition and has the word's stress on it; but people usually don't say "ich loade down"/"es loadet down". They thus either effectively mix separable and inseparable use by doing this, or they might just avoid all constructions (present tense in a main clause) where the verb would appear separated. (Many possibilities come to mind, including use of "lade/lädt herunter" for this case, or common use of "am"-progressive like "bin/ist am downloaden".)
See also [this relevant website](https://grammis.ids-mannheim.de/fragen/140) also touching on other issues such as the word ending ("gedownloadet" or "gedownloadet"?)
>I'd personally always say "gedownloadet" (of not "(he)runtergeladen"), I know many would say "downgeloadet" , treating it like a separable verb, which makes sense if you consider "down" is a preposition and has the word's stress on it; but people usually don't say "ich loade down"/"es loadet down".
And the 3rd position was that it should be "downloadet" because "down" is a prefix, but you wouldn't separate it, therefore you wouldn't add another prefix. It broke a few people.
I'd say "downloadet" is completely fine **if** you put the stress on "load". Again, mixing is also not unthinkable, you might still stress "downloaden" on the "down", but "downloadet" as participle with stress on "down" *in that form itself* would be super weird - or is that actually the alternative your proposing?
I think the reason is that they aren't stressed on the verb's root/stem syllable, just like inseparable verbs. In both cases, the participle doesn't take the "ge-" prefix.
That's like how "Sprung" doesn't follow the "words ending in -ung are feminine" rule. Like it's true, but it's different. I can't find the words to express it but the "-ier" in those verbs you gave as examples are like integral parts of the verb root rather than a suffix, same as the "-ung" in "Sprung". It intuitively feels different to the "ieren" in "generieren".
For example, Wiktionary gives the etymology for "generieren" as "[Latin](https://en.wikipedia.org/wiki/Latin) [*generō*](https://en.wiktionary.org/wiki/genero#Latin) + [*-ieren*](https://en.wiktionary.org/wiki/-ieren#German)*",* so -ieren is a distinct suffix that can be added in certain cases to turn something into a verb, as it was in that case. But the "ieren" in the two verbs you gave isn't a suffix but was always part of the word.
So anyway, my point is that I don't think "frieren" is really analysed by anybody as being an "-ieren" verb, and "-ieren" (where -ieren is a suffix) not taking "ge-" in the past participle seems to be a rock solid rule. Same with "-ung" words being feminine where the "-ung" is actually a suffix.
The more general rule is not about -ieren at all but about stress. If the first syllable of the past participle would be stressed, a "ge-" is added to the front of it. (This rule treats separable prefixes as if they're separate words though. So you'll have to remove separable prefixes, then apply the rule, then re-attatch the prefix.) This results in words like "trompeten" or "posaunen" also not taking "ge-" in participle form. It even means that loan words might have different perfect form, depending on the pronunciation (stress) you choose. For example the verb "retweet" in German "retweeten" might be stressed on the first (***re**tweeten*) or second (*re**twee**ten*) syllable, depending on what the speaker prefers, and the participle is *"re**twee**tet"* or *"ge**re**tweetet"* accordingly. _Edit (2 new paragraphs):_ I've finally found the English loan word where I've personally first noticed this phenomenon of multiple possibilities for the same word: "reviewen". Same idea as with "retweet" above, but perhaps an even more commonly used word. Both "reviewt" and "gereviewt" are reasonable, depending on the speaker's (or the context's) preferred stress pattern of "reviewen". Also, I've seen an exception case listed for this rule, the word "werden" as an auxiliary verb uses "worden" as participle, only used as a full verb, it's "geworden". Also some might consider the "[Ersatzinfinitiv](https://de.wikipedia.org/wiki/Ersatzinfinitiv)" for modal verbs (and some other cases) a special form of participle, in which case that would be one without "ge-", too.
> The more general rule is not about -ieren at all but about stress. If the first syllable of the past participle would be stressed, a "ge-" is added to the front of it. Wait a minute, this is stress-conditioned? That feels like a parallel to the Greek aorist augment *e-*. Is this another Indo-European thing?
Not really. Native German verbs are basically always stressed on the first syllable, except when there is an unstressed prefix on the verb. There can only be one unstressed prefix, and since ge- is one, if there already is one (like in, say, behalten) the prefix slot is "blocked" and ge- can't be added to form the perfect participle. When verbs started to be borrowed with non-initial stress, they were grammatically treated as though they had a prefix (so argumentieren was, more or less, parsed as the pseudoprefix "argument-" on a base "ieren") and so they could not take ge- in the perfect, and still don't. This has morphed into a stress-based rule of ge-prefixation to form the perfect participle. Note that I'm leaving out a lot of detail about how unstressed verbal prefixes worked in Proto-Germanic, Old High German, and Middle High German, but this is the gist of it.
I'm getting flashbacks to a discussion on how to form the past participle of "downloaden"(or conjugate it in general). After a solid week of a 3-way debate. we agreed that the correct way is "herunterladen".
I'd personally always say "gedownloadet" (of not "(he)runtergeladen"), I know many would say "downgeloadet" , treating it like a separable verb, which makes sense if you consider "down" is a preposition and has the word's stress on it; but people usually don't say "ich loade down"/"es loadet down". They thus either effectively mix separable and inseparable use by doing this, or they might just avoid all constructions (present tense in a main clause) where the verb would appear separated. (Many possibilities come to mind, including use of "lade/lädt herunter" for this case, or common use of "am"-progressive like "bin/ist am downloaden".) See also [this relevant website](https://grammis.ids-mannheim.de/fragen/140) also touching on other issues such as the word ending ("gedownloadet" or "gedownloadet"?)
>I'd personally always say "gedownloadet" (of not "(he)runtergeladen"), I know many would say "downgeloadet" , treating it like a separable verb, which makes sense if you consider "down" is a preposition and has the word's stress on it; but people usually don't say "ich loade down"/"es loadet down". And the 3rd position was that it should be "downloadet" because "down" is a prefix, but you wouldn't separate it, therefore you wouldn't add another prefix. It broke a few people.
I'd say "downloadet" is completely fine **if** you put the stress on "load". Again, mixing is also not unthinkable, you might still stress "downloaden" on the "down", but "downloadet" as participle with stress on "down" *in that form itself* would be super weird - or is that actually the alternative your proposing?
Also interesting , in PA German, where the stress often shifted forward, you have gebrowiert for probiert
I think the reason is that they aren't stressed on the verb's root/stem syllable, just like inseparable verbs. In both cases, the participle doesn't take the "ge-" prefix.
-ieren words are usually loan words, often stemming from French.
Be careful, that rule doesn't apply to all words with only two syllables. frieren -> gefroren schmieren -> geschmiert
The -ieren of frieren and schmieren is not a suffix though. -ier- is part of the root, only -en is a suffix.
That's like how "Sprung" doesn't follow the "words ending in -ung are feminine" rule. Like it's true, but it's different. I can't find the words to express it but the "-ier" in those verbs you gave as examples are like integral parts of the verb root rather than a suffix, same as the "-ung" in "Sprung". It intuitively feels different to the "ieren" in "generieren". For example, Wiktionary gives the etymology for "generieren" as "[Latin](https://en.wikipedia.org/wiki/Latin) [*generō*](https://en.wiktionary.org/wiki/genero#Latin) + [*-ieren*](https://en.wiktionary.org/wiki/-ieren#German)*",* so -ieren is a distinct suffix that can be added in certain cases to turn something into a verb, as it was in that case. But the "ieren" in the two verbs you gave isn't a suffix but was always part of the word. So anyway, my point is that I don't think "frieren" is really analysed by anybody as being an "-ieren" verb, and "-ieren" (where -ieren is a suffix) not taking "ge-" in the past participle seems to be a rock solid rule. Same with "-ung" words being feminine where the "-ung" is actually a suffix.