Twice as big (de două ori mai mare, dublu)

Twice as big: de două ori mai …

You know de două ori (twice) from saying how often: de două ori pe zi. Put it in front of a comparative and it multiplies: de două ori mai mare = twice as big. Change the number for three times, ten times: de trei ori mai scump, de zece ori mai mult. The rest is the comparison you already know: mai + adjective, and decât before whatever you compare with. Where English says as big as, Romanian keeps mai … decât.

Mult agrees, and big numbers take de

In de zece ori mai mult, mult is an adverb (ten times as much) and never changes. In front of a noun it agrees with that noun: de zece ori mai *mulți bani, de două ori mai **multă apă. From twenty up, the number takes *de, as it does before any noun: de douăzeci de ori mai scump.

Dublu, triplu

Dublu (double) and triplu (triple) are ordinary adjectives. They normally follow the noun and agree with it:

At a Romanian hotel you book a cameră dublă (a room for two) or a cameră triplă (for three), and a double bed is a pat dublu. A salariu dublu (double pay) is simply a salary that is de două ori mai mare.

Paying double

Like many adjectives, dublu also works as an adverb with no ending: am plătit dublu (I paid double). With the definite article it becomes a noun, dublul (the double): zece este dublul lui cinci.