How does the passive form of "to invite" work?


So I've got my tables of verb conjugations and I've settled down with "Read
Real Japanese", the short story edition, and the very first verb in the first
story is さそう - to invite - used in the passive. This is presented as さそわれて and
translated as "having been invited by..."

I've spent a couple of days searching the Internet and piles of books but
although I have been able to find other examples of this verb being conjugated
this way, I can't find any explanation. Surely さそう is a ru-verb [edit: I see
that this was a confusion caused by differing terminology] and conjugates in
the passive to さそられる?

I can sort of see that ら might become わ under some circumstances (but I don't
know what they might be) but how or why would る become て?

What's going on here?




I'm going to try to do two things in this answer. First, I'm going to try to
address the tangle of terms and theories that have got you confused. (So this
answer will unfortunately be rather long!) Second, I'll try to address the
specific question of 誘う.

Feel free to skip any section that doesn't look immediately helpful :-)

* * *

# What do ' _-u_ verb' and ' _-ru_ verb' mean?

The terms ' _-u_ verb' and ' _-ru_ verb' only make sense in rōmaji:

  1. ## _-u_ verbs

Verbs such as 泳ぐ can be divided into _oyog- **u_** :

[code]     　泳がない　oyo **g** -anai

    　泳ぎます　oyo **g** -imasu
    　泳ぐ　　　oyo **g** - **u**
    　泳げば　　oyo **g** -eba
    　泳ごう　　oyo **g** -oo
    
[/code]

The **stem** is _oyog-_ , which ends in the **consonant** /g/.

So in linguistics, these are often called **'consonant-stem verbs'**.

* * *

  2. ## _-ru_ verbs

Verbs such as 食べる can be divided into _tabe- **ru_** :

[code]     　食べない　tab **e** -nai

    　食べます　tab **e** -masu
    　食べる　　tab **e** - **ru**
    　食べれば　tab **e** -reba
    　食べよう　tab **e** -yoo
    
[/code]

The **stem** is _tabe-_ , which ends in the **vowel** /e/.

So in linguistics, these are often called **'vowel-stem verbs'**.

* * *

# _-ru_ is not る

Verbs that end in the kana る aren't always _-ru_ verbs. We saw 食べる _tabe-
**ru_** above, and that's definitely a _-ru_ verb.

But let's take a look at 図る _hakar- **u_** :

[code]

    　図らない　haka **r** -anai
    　図ります　haka **r** -imasu
    　図る　　　haka **r** - **u**
    　図れば　　haka **r** -eba
    　図ろう　　haka **r** -oo
    
[/code]

As you can see, even though this ends in the kana る, it conjugates like an
_-u_ verb.

Unfortunately, this point can be very confusing for people who see the terms
_-u_ and _-ru_ without an explanation about rōmaji!

* * *

## When the verb stem ends in /w/

Your verb, 誘う _sasow-_ , is somewhat special. In Modern Japanese, the
consonant /w/ disappears before all vowels except /a/. The conjugation looks
like this:

[code]

    　誘わない　saso **w** -anai
    　誘います　saso **w** -imasu **** →　saso-imasu   (/w/ disappears)
    　誘う　　　saso **w** - **u**      →　saso- **u**       (/w/ disappears)
    　誘えば　　saso **w** -eba ****  →　saso-eba     (/w/ disappears)
    　誘おう　　saso **w** -oo  ****  →　saso-oo      (/w/ disappears)
    
[/code]

And of course, 誘われる _sasow-areru_ works the same way as 誘わない _sasow-anai_. The
/w/ is followed by /a/, so it doesn't disappear.

* * *

# 一段 and 五段 verbs (the traditional analysis)

In traditional grammar, this was of course analyzed very differently! The
smallest unit they divided Japanese into was not the phoneme, but the kana.
With kana alone, it wasn't possible for them to indicate that the /w/ of
_sasow-_ or the /g/ of _oyog-_ belonged to the stem.

Instead, they naturally concluded that each verb had multiple surface forms to
which auxiliaries such as ～ます and ～ない attached.

  1. ## 五段 (Godan) verbs

Let's take a look at your example of 誘う and see how it's traditionally broken
down:

[code]     　誘 **わ** ＋ない　saso **wa** -nai

    　誘 **い** ＋ます　saso **i** -masu
    　誘 **う**　　　　saso **u**
    　誘 **え** ＋ば　　saso **e** -ba
    　誘 **お** ＋う　　saso **o** -o
    
[/code]

Here we find five different kana, わ・い・う・え・お, one from each vowel row. The
vowel rows in [the kana chart](https://en.wikipedia.org/wiki/Goj%C5%ABon) are
called 段, so this is traditionally called a 五段 (five-row) verb.

In this analysis, the わ is simply an exception. With other 五段 verbs, you'll
find the kana more or less as you expect:

[code]     　編 **ま** ＋ない　a **ma** -nai

    　編 **み** ＋ます　a **mi** -masu
    　編 **む**　　　　a **mu**
    　編 **め** ＋ば　　a **me** -ba
    　編 **も** ＋う　　a **mo** -o
    
[/code]

Here we have ま・み・む・め・も, all from the same consonant column. Again we find one
kana from each vowel row, so again this is a 五段 (five-row) verb.

  2. ### 一段 (Ichidan) verbs

Next, let's look at how a vowel-stem verb is traditionally broken down:

[code]     　食 **べ**　＋ない　ta **be**  -nai

    　食 **べ**　＋ます　ta **be**  -masu
    　食 **べ** る　　　　ta **be** ru
    　食 **べ** れ＋ば　　ta **be** re-ba
    　食 **べ**　＋よう　ta **be**  -yoo
    
[/code]

Here we just find one kana, べ, which belongs to one vowel column. And so, this
is traditionally called an 一段 (one-row) verb.

Of course, there's a lot more to talk about in traditional grammar. My goal
here is just to show you where 一段 and 五段 come from. Hopefully this is enough
:-)

* * *

# A terminological mess

Ignoring the theory, regular verbs break down broadly into the following two
groups. These groups have been given many names by grammarians, linguists, or
just people trying to make things easier for learners:

### Verbs like 泳ぐ _oyog-u_

  1. 五段 verb
  2. consonant-stem verb
  3. _-u_ verb
  4. Group I verb

### Verbs like 食べる _tabe-ru_

  1. 一段 verb
  2. vowel-stem verb
  3. _-ru_ verb
  4. Group II verb

But whatever labels and theories you use, they're the same two groups of
verbs. I know it's confusing that everyone uses different terms, but I hope
I've managed to straighten out all the different terms people throw around!




I'm going to try to do two things in this answer. First, I'm going to try to
address the tangle of terms and theories that have got you confused. (So this
answer will unfortunately be rather long!) Second, I'll try to address the
specific question of 誘う.

Feel free to skip any section that doesn't look immediately helpful :-)

* * *

# What do ' _-u_ verb' and ' _-ru_ verb' mean?

The terms ' _-u_ verb' and ' _-ru_ verb' only make sense in rōmaji:

  1. ## _-u_ verbs

Verbs such as 泳ぐ can be divided into _oyog- **u_** :

[code]     　泳がない　oyo **g** -anai

    　泳ぎます　oyo **g** -imasu
    　泳ぐ　　　oyo **g** - **u**
    　泳げば　　oyo **g** -eba
    　泳ごう　　oyo **g** -oo
    
[/code]

The **stem** is _oyog-_ , which ends in the **consonant** /g/.

So in linguistics, these are often called **'consonant-stem verbs'**.

* * *

  2. ## _-ru_ verbs

Verbs such as 食べる can be divided into _tabe- **ru_** :

[code]     　食べない　tab **e** -nai

    　食べます　tab **e** -masu
    　食べる　　tab **e** - **ru**
    　食べれば　tab **e** -reba
    　食べよう　tab **e** -yoo
    
[/code]

The **stem** is _tabe-_ , which ends in the **vowel** /e/.

So in linguistics, these are often called **'vowel-stem verbs'**.

* * *

# _-ru_ is not る

Verbs that end in the kana る aren't always _-ru_ verbs. We saw 食べる _tabe-
**ru_** above, and that's definitely a _-ru_ verb.

But let's take a look at 図る _hakar- **u_** :

[code]

    　図らない　haka **r** -anai
    　図ります　haka **r** -imasu
    　図る　　　haka **r** - **u**
    　図れば　　haka **r** -eba
    　図ろう　　haka **r** -oo
    
[/code]

As you can see, even though this ends in the kana る, it conjugates like an
_-u_ verb.

Unfortunately, this point can be very confusing for people who see the terms
_-u_ and _-ru_ without an explanation about rōmaji!

* * *

## When the verb stem ends in /w/

Your verb, 誘う _sasow-_ , is somewhat special. In Modern Japanese, the
consonant /w/ disappears before all vowels except /a/. The conjugation looks
like this:

[code]

    　誘わない　saso **w** -anai
    　誘います　saso **w** -imasu **** →　saso-imasu   (/w/ disappears)
    　誘う　　　saso **w** - **u**      →　saso- **u**       (/w/ disappears)
    　誘えば　　saso **w** -eba ****  →　saso-eba     (/w/ disappears)
    　誘おう　　saso **w** -oo  ****  →　saso-oo      (/w/ disappears)
    
[/code]

And of course, 誘われる _sasow-areru_ works the same way as 誘わない _sasow-anai_. The
/w/ is followed by /a/, so it doesn't disappear.

* * *

# 一段 and 五段 verbs (the traditional analysis)

In traditional grammar, this was of course analyzed very differently! The
smallest unit they divided Japanese into was not the phoneme, but the kana.
With kana alone, it wasn't possible for them to indicate that the /w/ of
_sasow-_ or the /g/ of _oyog-_ belonged to the stem.

Instead, they naturally concluded that each verb had multiple surface forms to
which auxiliaries such as ～ます and ～ない attached.

  1. ## 五段 (Godan) verbs

Let's take a look at your example of 誘う and see how it's traditionally broken
down:

[code]     　誘 **わ** ＋ない　saso **wa** -nai

    　誘 **い** ＋ます　saso **i** -masu
    　誘 **う**　　　　saso **u**
    　誘 **え** ＋ば　　saso **e** -ba
    　誘 **お** ＋う　　saso **o** -o
    
[/code]

Here we find five different kana, わ・い・う・え・お, one from each vowel row. The
vowel rows in [the kana chart](https://en.wikipedia.org/wiki/Goj%C5%ABon) are
called 段, so this is traditionally called a 五段 (five-row) verb.

In this analysis, the わ is simply an exception. With other 五段 verbs, you'll
find the kana more or less as you expect:

[code]     　編 **ま** ＋ない　a **ma** -nai

    　編 **み** ＋ます　a **mi** -masu
    　編 **む**　　　　a **mu**
    　編 **め** ＋ば　　a **me** -ba
    　編 **も** ＋う　　a **mo** -o
    
[/code]

Here we have ま・み・む・め・も, all from the same consonant column. Again we find one
kana from each vowel row, so again this is a 五段 (five-row) verb.

  2. ### 一段 (Ichidan) verbs

Next, let's look at how a vowel-stem verb is traditionally broken down:

[code]     　食 **べ**　＋ない　ta **be**  -nai

    　食 **べ**　＋ます　ta **be**  -masu
    　食 **べ** る　　　　ta **be** ru
    　食 **べ** れ＋ば　　ta **be** re-ba
    　食 **べ**　＋よう　ta **be**  -yoo
    
[/code]

Here we just find one kana, べ, which belongs to one vowel column. And so, this
is traditionally called an 一段 (one-row) verb.

Of course, there's a lot more to talk about in traditional grammar. My goal
here is just to show you where 一段 and 五段 come from. Hopefully this is enough
:-)

* * *

# A terminological mess

Ignoring the theory, regular verbs break down broadly into the following two
groups. These groups have been given many names by grammarians, linguists, or
just people trying to make things easier for learners:

### Verbs like 泳ぐ _oyog-u_

  1. 五段 verb
  2. consonant-stem verb
  3. _-u_ verb
  4. Group I verb

### Verbs like 食べる _tabe-ru_

  1. 一段 verb
  2. vowel-stem verb
  3. _-ru_ verb
  4. Group II verb

But whatever labels and theories you use, they're the same two groups of
verbs. I know it's confusing that everyone uses different terms, but I hope
I've managed to straighten out all the different terms people throw around!

