Question 誰も大きな箱を動かすことができない。

[Zizka]

In the sentence above, why is ことが necessary? If I say "No one can move the box" the verb hasn't been nominalised. So why is ことが necessary?

 

[Toritoribe]

"Dictionary form of verb + ことができる" is a potential form, so 動かすことができない is an alternative to 動かせない. The literal translation of 動かすことができない is "can't do moving", so it's the same as "can't move" as a result. If ことが is removed, it's 動かすできない. This is ungrammatical.

 

[Zizka]

So dictionary form +ことができる is another grammatical structure not to be confused with っことがある. The 'potential form' expresses whether or not we have the ability to do something or not.

動かせない is the 'causative' inflection of the verb 動く. The 'causative' is:
" In English grammar, a causative verb is a verb used to indicate that some person or thing makes—or helps to make—something happen. Examples of causative verbs include (make, cause, allow, help, have, enable, keep, hold, let, force, and require), which can also be referred to as causal verbs or simply causatives. "

I don't understand why you say that 動かせない is an alternative to the potential form. How is it a substitute in the sentence? I don't understand what you're trying to say. How is a causative and alternative to a potential form?

 

[SomeCallMeChris]

So dictionary form +ことができる is another grammatical structure not to be confused with っことがある. The 'potential form' expresses whether or not we have the ability to do something or not.

Yes.

" In English grammar, a causative verb is a verb used to indicate that some person or thing makes—or helps to make—something happen. Examples of causative verbs include (make, cause, allow, help, have, enable, keep, hold, let, force, and require), which can also be referred to as causal verbs or simply causatives. "

That's a definition for English grammar. The Japanese causative has a broader meaning than the English causative. (... or so I always thought. That definition seems plenty broad though. Interesting.) But anyway it's a definition for a class of verbs, not for a conjugation.

I don't understand why you say that 動かせない is an alternative to the potential form. How is it a substitute in the sentence?

Because your interpretation of 動かせない is wrong. Torotoribe-san was not talking about 動く, he was talking about your example sentence.

Also you have what is an alternative to what exactly backwards. I recommend reading Toritoribe-san's post again.

 

[Toritoribe]

動かせない is the 'causative' inflection of the verb 動く.

Note that not all conjugation forms of verbs are really used. 動かせる is only used as the potential form of 動かす, and it's never used as the causative form of 動く. Instead, 動かす works as the causative form of 動く.

The same goes with 沸かせる, 乾かせる, 減らせる and 照らせる. These forms are only used as the potential form of 沸かす, 乾かす, 減らす and 照らす, and they are never used as the causative form of 沸く, 乾く, 減る and 照る, respectively.

 

[Zizka]

Note that not all conjugation forms of verbs are really used. 動かせる is only used as the potential form of 動かす, and it's never used as the causative form of 動く. Instead, 動かす works as the causative form of 動く.

I understand that bit. 動かせる （うごかせる）is only used for the potential form. So when you 'can/can't' move something, I'll use that form. If I say for example that someone made me move something ('causative'), I'll use 動かす instead.

Also you have what is an alternative to what exactly backwards.

I don't understand this sentence. Did you mean to say to 'that' exactly backwards?

But anyway it's a definition for a class of verbs, not for a conjugation.

What do you mean?

 

[Toritoribe]

If I say for example that someone made me move something ('causative'), I'll use 動かす instead.

Not really. Notice that 動く is intransitive, so the causative form means "subject makes someone/something move". What you wrote is the function of the causative form of the transitive verb 動かす, i.e., 動かさせる. Actually, this form is not so commonly used. Other expressions like 動かすようにさせる are more preferred.

 

[SomeCallMeChris]

I don't understand this sentence. Did you mean to say to 'that' exactly backwards?

Ehh. I guess I was wrong to say backwards, Toritoribe-san did call ～ことができる "a potential form".

The point I was getting at is that 動かせる is the potential conjugation of 動かす. It's not an alternative to "the potential form", it is a potential form.

What do you mean?

Your quote begins, "In English grammar, a causative verb is ..."

It's not a definition for the word causative in general, or causative grammars in general, or even causative grammars in the English language.

It's a definition for a particular set of verbs in the English language.

It does have strong parallels to the Japanese causative conjugation, but you cannot take it as a definition of the Japanese causative conjugation. For that, you would be better served to carefully read the chapter(s) in your textbook that cover the causative, and/or the appropriate entry in ADoBJG.