Negative sentences

Question

Oil is one of the world's major sources of energy.

I'm supposed to rewrite this sentence as a negative sentence, that is, a sentence that means the same thing but uses a negation.

I've thought of two possible ways to do this:

• Oil is not one of the world's minor sources of energy.
• Not many sources of energy are as major as oil.

I've been told that the first one is wrong because major is used in a comparative degree, but I think it's positive. If I do the same for "Steve is taller than him" I get "Steve is not shorter than him" which is not the same sentence because Steve could be taller or just as tall as him, so this transformation is not valid for the comparative degree. My query is whether "one of the world's major sources" is comparative, because then it would be wrong.

Can someone tell me if either of these sentences is correct? Is there another way to do this?

Some other examples:

1. It is useless.
   It is not useful.

2. They had always fallen into the realm of possibility.
   They had never fallen into the realm of impossibility.

3. He likes to go to the seashore.
   He doesn't dislike going to the seashore.

Answer 1

At first glance it seems like major should be a comparative adjective because it implies that it is "better" or "more" than something else, but that isn't really what comparative means.

Major and minor aren't quite comparable to short and tall in this sense, because the latter adjectives have comparative forms: i.e. shorter, shortest, taller, tallest. Majorer and majorest are of course not real words.

Honestly I don't think either of your sentences are wrong, though the first one sounds more natural than the second. If you wanted another opinion, you could also try something like:

Oil is not a lesser source of energy for the world.

Answer 2

My query is whether "one of the world's major sources" is comparative, because then it would be wrong.

No. Comparatives require an expressed or implied than X - basically, you need 2 things when comparing.

Answer 3

Both your examples are technically correct but do not sound idiomatic, partly because of your use of the words "major" and "minor". Forcing a negation is difficult as it can sound unnatural.

As a native English speaker I would prefer:

Not many sources of energy are as widely used as oil.

(although I would probably say "few" rather than "not many", but that might not be considered a negation by your tutor.

Oil should not be discounted from among the world's major sources of energy.

(a bit contrived)

Oil is not a minor energy source, but is one of the world's major sources of energy.

(this sounds a little bit more natural to me than the similar example you gave)