My sister is one year old.
Watergate was a huge scandal when Nixon was president.
a sentence you can use is: Anyone can become a superstar if they wanted to.
One uses the generalised pronoun ONE in place of the generalîsed pronoun YOU - which is what we tend to use in ordinary informal conversation, unless one went (unless you went) to Eton College or...
On a clear night you can easily study the stars whereas on a cloudy night it is quite difficult.