9:45 in Engpsh can be expressed in two ways:

"nine forty-five"
"quarter to ten"

The first expression "nine forty-five" is a direct translation from the numerical representation of time. This is the most commonly used way of expressing time in Engpsh.

The second expression "quarter to ten" is based on the way that time is traditionally told using the face of a clock. This expression is used less frequently than the first, but it is still widely understood.

Example sentences:

"I will meet you at nine forty-five." (我将在9:45与你见面。)
"The movie starts at a quarter to ten." (电影在10点差15分开始。)