The number nineteen in English is written as "nineteen." It comes from the Old English word "nigontyne," which is a combination of the words "nigon" (meaning "nine") and "tyne" (meaning "ten"). Here are some example sentences using the word "nineteen" in English:

"The book has nineteen chapters." (这本书有十九章。)

"My daughter turned nineteen last week." (我女儿上周满十九岁了。)

"We need nineteen cups for the party." (我们需要十九个杯子来开派对。)