Is there a historical explanation why verbs fall into two categories of pitch accent?


Is there a good historical or logical explanation why all verbs fall into two
categories of pitch accent: either accentless (such as 買う, 浴びる) or accented
(such as 食べる, 書く)?

I am having a hard time memorising the pitch accent of each and every single
verb because the distribution seems so random to my brain, so I am hoping that
a historical explanation might shed some light on the phenomenon… and thus
make it easier to memorise them…

In the past I have often found that historical / logical explanations can
really clear up things in that sense.

Thanks!




The distinction goes as far back as we have data. Already in Middle Japanese
(MJ, Heian period) the verbs were divided into two classes, one with the stem
melody LL…LH-, the other HH…HL-;¹ that is, they had a mostly flat pitch, and
flipped the tone at the very last mora.² These two patterns correspond, to a
great extent, to classes A and B in modern dialects (with a few verbs
switching classes here and there). We don’t have tone data for Japanese before
this period, so there’s no clear picture of how it evolved. But the reason why
all verbs fall into two accent classes is surely that the accents (at the end
of the day, a restricted tone system), in all their numerous dialectal
variants, have developed from these 2 older tone patterns.

In the case of nouns, the MJ tone system was richer; it had more distinctions
than than modern Japanese dialects. But for verbs (and i-adjectives) it only
had 2 classes, like its modern reflexes. AFAIK there’s no definitive answer as
to why. Martin speculates that maybe verbs were all created with some sort of
formant morphemes, now lost, and those levelled the melodies into the 2
simpler patterns. However that may be, I don’t think there’s any obvious
explanation anymore as to why a given verb is A or B.

Notice however that having only 2 word melodies is a common pattern, cross-
linguistically; Norwegian and Swedish do it, and in Japan Kagoshima and some
Ryūkyūan languages evolved in that direction for all words, nouns included.
Moreover, having different tonal rules for uninflected and inflected words, as
MJ did, is not unheard of, either; Navajo does much the same.

By the way, I’d suggest not worrying too much about _deliberately_ memorizing
the accent locations.

Notes:

1) In the Kindaichi reconstruction class A (e.g. modern _umaru_ ) in MJ starts
high and flips to low before a suffix: _úmárì-té_ , HHL-H. In the Ramsey
reconstruction it was the opposite, _ùmàrí-tè_ , LLH-L. And class B (e.g.
_urámu_ ) was exactly the other way around: _ùràmí-té_ LLH-H for Kindaichi,
HHL-L _úrámì-tè_ for Ramsey.

2) In class B verbs with ≥4 moræ, the switch happened one mora earlier: modern
_ayamátsu_ < MJ _àyàmátì-té_ LLHL-L (Kindaichi) / _áyámàtí-tè_ HHLH-L
(Ramsey). Compare modern anticipations of class B vowel-stem verbs: _okíru_ /
_ókite_ , _awaséru_ / _awásete_.

Under the Ramsey reconstruction, the first HL drop in the MJ melody became the
Tokyo accent (this works for the various noun classes, too). So class B ends
up with the accent on the penultimate because the basic MJ pattern, HH…HL-,
gives you an HL drop at the penultimate. And class A ended up unaccented
because there was no HL drop within the stem, LLL…LH-. (Notice however that MJ
class A dropped the pitch _after_ the stem, so we could expect class A in
Tokyo to end up final-accented; and, interestingly, we actually do have a drop
following A verbs (unlike unaccented nouns), though it shifts to the suffix if
there's one: _hajimeru˺ga_ , _hajime˺wa_ , _hajimeta˺ga_ ; _ireru˺ga_ ,
_ire˺wa_ , _ireta˺ga_ , etc.)




The distinction goes as far back as we have data. Already in Middle Japanese
(MJ, Heian period) the verbs were divided into two classes, one with the stem
melody LL…LH-, the other HH…HL-;¹ that is, they had a mostly flat pitch, and
flipped the tone at the very last mora.² These two patterns correspond, to a
great extent, to classes A and B in modern dialects (with a few verbs
switching classes here and there). We don’t have tone data for Japanese before
this period, so there’s no clear picture of how it evolved. But the reason why
all verbs fall into two accent classes is surely that the accents (at the end
of the day, a restricted tone system), in all their numerous dialectal
variants, have developed from these 2 older tone patterns.

In the case of nouns, the MJ tone system was richer; it had more distinctions
than than modern Japanese dialects. But for verbs (and i-adjectives) it only
had 2 classes, like its modern reflexes. AFAIK there’s no definitive answer as
to why. Martin speculates that maybe verbs were all created with some sort of
formant morphemes, now lost, and those levelled the melodies into the 2
simpler patterns. However that may be, I don’t think there’s any obvious
explanation anymore as to why a given verb is A or B.

Notice however that having only 2 word melodies is a common pattern, cross-
linguistically; Norwegian and Swedish do it, and in Japan Kagoshima and some
Ryūkyūan languages evolved in that direction for all words, nouns included.
Moreover, having different tonal rules for uninflected and inflected words, as
MJ did, is not unheard of, either; Navajo does much the same.

By the way, I’d suggest not worrying too much about _deliberately_ memorizing
the accent locations.

Notes:

1) In the Kindaichi reconstruction class A (e.g. modern _umaru_ ) in MJ starts
high and flips to low before a suffix: _úmárì-té_ , HHL-H. In the Ramsey
reconstruction it was the opposite, _ùmàrí-tè_ , LLH-L. And class B (e.g.
_urámu_ ) was exactly the other way around: _ùràmí-té_ LLH-H for Kindaichi,
HHL-L _úrámì-tè_ for Ramsey.

2) In class B verbs with ≥4 moræ, the switch happened one mora earlier: modern
_ayamátsu_ < MJ _àyàmátì-té_ LLHL-L (Kindaichi) / _áyámàtí-tè_ HHLH-L
(Ramsey). Compare modern anticipations of class B vowel-stem verbs: _okíru_ /
_ókite_ , _awaséru_ / _awásete_.

Under the Ramsey reconstruction, the first HL drop in the MJ melody became the
Tokyo accent (this works for the various noun classes, too). So class B ends
up with the accent on the penultimate because the basic MJ pattern, HH…HL-,
gives you an HL drop at the penultimate. And class A ended up unaccented
because there was no HL drop within the stem, LLL…LH-. (Notice however that MJ
class A dropped the pitch _after_ the stem, so we could expect class A in
Tokyo to end up final-accented; and, interestingly, we actually do have a drop
following A verbs (unlike unaccented nouns), though it shifts to the suffix if
there's one: _hajimeru˺ga_ , _hajime˺wa_ , _hajimeta˺ga_ ; _ireru˺ga_ ,
_ire˺wa_ , _ireta˺ga_ , etc.)

