Trying to understand the other gender.
I have read the Half Blood Prince More than twenty times ... there isn't a complication. But thanks for asking WIKI ANSWERS your question!
Twenty is a score so twenty years is a score of years.
Twenty Years After was created in 1845.
Joseph was either in prison for twenty years or in Egypt for twenty years. But I think it was Joseph in Egypt for twenty years.
Twenty Years of Dirt was created in 1986.
Twenty One Years was created in 2006.
Twenty Good Years was created in 2006.
The Twenty Years' Crisis was created in 1939.
Musketeers Twenty Years After was created in 1992.
That is the correct spelling of the period of "twenty-seven years" (27 years).
Twenty years old is はたち
The word for every twenty years is "score."