[Grammar] can I say 'don't have to' with 'can'?

[mmasny]

In Polish we have a distinction between 'not can do sth' and 'can not do sth' (I translated it literally, leaving the word order unchanged). In the first 'not' negates 'can' so it means 'cannot do sth', in English. In the second 'not' is related to 'do' so it means 'do not have to'. It often causes problems, for as you see the Polish 'can not' means something different from English 'cannot'.
So my question is: can I say 'I don't have to do it' using the verb 'can'? In fact I would find it very wierd if I couldn't and I think there must be a proper word order or something that allows to negate 'do' instead of 'can'.

 

[Linguist__]

In the first 'not' negates 'can' so it means 'cannot do sth', in English. In the second 'not' is related to 'do' so it means 'do not have to'.

(Not a teacher)

So, you've said the first Polish translation - 'not can do something' - equates to English - 'Can't do something'. You are wondering if there is a way to say 'don't have to do something' using 'can', I think?

You could say 'I can not do something'. It is more a rhetorical use than practical, however:

Person 1: You can read 'War and Peace' on the flight.
Person 2: Or, I can not read it, and watch a chick-flick instead.

Person 2 isn't negating 'can' in this sentence. If they were it would be 'I am not able to read it'. They are negating 'read', meaning that they won't read it. I say it is more rhetorical because it is usually a response to someone saying 'You can...'. It's purpose is to negate what the person said previously, I doubt it can be used in an utterance on it's own.

About a way for saying 'I don't have to do it' using 'can'; you could say 'I can't have to do it', but it would be a very specific occurance:

Person 1: You have to shake hands with the Queen when you meet her.
Person 2: I can't have to shake her hand, I don't have any arms!

 

[mmasny]

Oh, thank you, that's very helpful!
So, to make sure I got you right:
can I say 'I can do it or I can not do it', meaning 'Maybe I will do it, maybe I won't'?
I understand that the difference between denying the auxilliary and denying the verb (whose grammatical name I don't know) is putting the space between them in this particular case? This is a general problem, that I do not know how to solve, but am I right in this one?

 

[Linguist__]

You have it right, yes. You can negate any main verb this way by adding 'not' before it, and after the auxiliary.

I can not go.
I can not do.
I can not walk.

Realise, though, that these are rhetorical phrases. They are used to negate what a person has said previously, so:

Person 1: You can go to the party and enjoy yourself!
Person 2: Or, I can not go, and enjoy myself just as much in my house.

Person 1: You can do the exam, just try!
Person 2: Or, I can not do it, and save myself the embarrassment of looking stupid.

Person 1: You can walk to the shop.
Person 2: Or, I can not walk, and take the car instead.

I hope you understand how this construction is used. Perhaps it would be appropriate to say it is colloquial/informal/not standard. Certainly, it isn't a polite thing to say in response to someone. Let's see what the experts say.

 

[gabber]

Mmasny,
You could say "I can refuse to do it," or "I can refrain from doing it," or "I can simply not do it."

 

[mmasny]

You have it right, yes. You can negate any main verb this way by adding 'not' before it, and after the auxiliary.

I can not go.
I can not do.
I can not walk.

Realise, though, that these are rhetorical phrases. They are used to negate what a person has said previously, so:

Person 1: You can go to the party and enjoy yourself!
Person 2: Or, I can not go, and enjoy myself just as much in my house.

Person 1: You can do the exam, just try!
Person 2: Or, I can not do it, and save myself the embarrassment of looking stupid.

Person 1: You can walk to the shop.
Person 2: Or, I can not walk, and take the car instead.

I hope you understand how this construction is used. Perhaps it would be appropriate to say it is colloquial/informal/not standard. Certainly, it isn't a polite thing to say in response to someone. Let's see what the experts say.

This is exactly what I needed. Thank you so much. Could someone clarify how much informal it is (I really hope not much )