请教: OG11-4, 怎么看double的词性和作用呢?(好像搞懂了)

helio5

double
predeterminer
twice as big, twice as much, or twice as many
double the amount/number/size etc
　We'll need double this amount for eight people.
　The value of the house is double what it was.

predeterminer
a word that is used before a determiner (=a word such as 'the', 'that', 'his' etc) . In the phrases 'all the boys' and 'both his parents', the words 'all' and 'both' are predeterminers.