Can we say "you can [not go] to school" or does it automatically become a negative sentence? [duplicate]

1. You can not go to school.

It's perfectly possible to use the sentence above to mean that not going to school is a possible option. Notice that usually the word cannot is written as one word. This anomaly is probably not an accident. Usually if we have an auxiliary that is not contracted with the negative word not, the auxiliary is not stressed, the stress falls on the word not. Notice that this isn't the case when we say cannot. The stress here falls on the first syllable, in other words on the auxiliary:

• You cannot go to school.

Compare this with, for example, with have:

• I've not finished yet.
• I have not finished yet.

When there's no contraction, the stress is standardly applied to the negative particle not; not to the auxiliary.

Now if we wish to negate the following verb instead of the auxiliary can, so that we mean that there's an option to not do something, all we need to do is stress the word not instead of the word can:

• You can not go.

Now if we were very strict about writing cannot as one word instead of two, then we would not need to use italics when we were writing such sentences to indicate the stress here. We could just use two words can not. However, we aren't all that strict about it at all, and so in order to not be misunderstood it is probably best to use italics when writing to highlight the marked pronunciation.

Now, the Original Poster wisely asked if using a sentence like the above will negate the whole sentence instead of just the verb go. The answer is that it won't. We might think that the sentence is negated, purely on the basis of the lexical verb being negated. This isn't the case. We can do a test here to establish the polarity of the sentence. Usually a negative sentence will take a positive question tag and vice versa:

• You've eaten it, haven't you? (positive sentence, negative tag)
• You haven't seen it, have you? (negative sentence, positive tag)

If we stick a tag on a normal sentence where can is negated we will see a positive tag:

• You can't do it, can you? (negative sentence, positive tag)

However, if we negate the lexical verb do in this example, instead, by using marked stress, then we get the following result:

• You can not do it though, can't you?

Here we see a negative tag, which is a clear sign that the sentence has a positive polarity when the lexical verb is negated.

Of course this is one option open to a writer, if the genre and style aimed for will allow it. They can just stick a tag on the question:

• You can not go, can't you!

Arguably, however, it might still be best to use italics here to prevent the reader from having to reread the sentence.

With suitable prosody, "You can not go to school" could mean "You are able not to go to school". But it is ambiguous, and without special stress it would probably be interpreted as "You cannot go to school".