你可以说 "I have long hair." 来表示你有长长的头发。
来源：在英语中，long是一个形容词，用来描述长度。
例句：
"My hair reaches my waist, so I have long hair."
(我的头发到腰，所以我有长长的头发。)
"She always wears her long hair in a ponytail."
(她总是把她长长的头发扎成马尾。)
"Long hair is a sign of beauty for many women."
(对许多女性来说，长发是美丽的标志。)