Page 380 - Practical English Usage 3ed - Michael Swan, Oxford

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In many British, American and other dialects, two or more negatives can be used with a single negative meaning.
I ain't seen nobody. (Standard English: I haven't seen anybody.)
I ain't never done nothing to nobody, and I ain't never got nothing from
nobody no time. (American song by Bert Williams) For more infonnation about a;,,'t, see 143.4.
two negative ideas: not ... or I not ... nor
When not refers to two or more verbs, nouns, adjectives etc, we usually join them with or.
He doesn't smoke or drink. (NOT He tltJesn't SfIIBke liB ' drink.) She wasn't angry or upset.
It's not on the table or in the cupboard.
However, we can use nor after a pause, to separate and emphasise a second verb, adjective etc.
Our main need is not food, nor money. It is education. (More emphatic than ... food or money.)
She didn't phone that day, nor the next day. (More emphatic than ... or the next day.)
Note that neither cannot be used in this way.
For the use of neither . •• nor to join two negative ideas (e.g. He /leither smokes /lor drinks).
see 373.
... I don't think etc
In informal speech, expressions like I don't think or I don't suppose are often added after negative statements. In this case, the extra negative makes no difference to the meaning of the statement.
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negative structures (4): double negatives 370
I opened the door, but I couldn't see anybody. (NOT ••• bitt" coltld see anyb6dy.)
Don't tell them anything.
Your suggestion won't help either of us.
At the beginning of a clause, only nobody, nothing etc are used. Nothing matters. (NOT N6t anything matters.)
Nowhere is safe.
3 double and multiple negatives and their meaning
Two or more negative words can be used in one clause, but then both words normally have their full meaning. Compare:
Say nothing. (= Be silent.)
Don't just say nothing. Tell us what the problem is. (= Don't be silent ...) Multiple negatives are sometimes used instead of simple positive structures for special stylistic effects. This is rather literary; in spoken English it can seem unnatural or old-fashioned.
Not a day passes when I don't regret not having studied music in my youth. (More natural: Every day I regret not having studied music when I was
younger. OR I wish I had studied music when I was younger.) 4 dialects
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