Most of my fellows believe that "two times larger than" means "three times as large as". However, I remember (dimmly) that an American teacher once said that "two times larger than" means "two times as large as". Can any one help me clarify that? Thanks!

Yes, this is right. It means exactly the same thing. This is wrong - three is a different number to two!

"two times larger than " is considered ambiguous by many people (although aes_uk is apparently not one of them) as in y=x + 2x OR y=2x. The words could mean " the amount by which y is larger than x (i.e. the difference by which it is larger) is two times (the value of) x " "two times as large as" is considered unambiguous y=2x

When I first read gladorient's question, I was sure of my answer but now you're making me wonder slightly if I might be mistaken. I've certainly never heard of this ambiguity but what you're saying makes sense. Maybe it would be best to stick to using "two times as large as" and then "three times as large as" and just not use the "larger than" construction as it seems to create confusion, for me at least!

Gladorient : I agree that is very good advice. If you ever hear this "larger than ..." you should immediately ask for clarification from the speaker. Wait till you find the threads on "three times smaller than"

Thanks a lot! What I am looking for is "native speakers' intuition". Your first reaction actually is most reliable. You don't look at a word for a whole day to figure out its meaning, do you? Further, is it possible that these constructions are used differently by the British and the Americans?

It seems that most native speakers tend to think the two expressions are basically the same at first sight, but some may hesitate on second thought. So the clearest way of sayig this is "twice as large as".