英语一个球怎么说

In Engpsh, a ball is generally referred to as "a ball." Some examples of sentences using "ball" in context might include:

"Can you pass me the ball?"
"I love playing with a ball in the park."
"The ball rolled under the couch."

It's also possible to specify the type of ball you're talking about by adding a modifier. For example:

"I'm going to play some basketball with my friends." (Here, "basketball" is the type of ball being used.)
"We were playing soccer with a football." (Here, "football" is another word for a soccer ball.)
"She has a collection of different balls, including a golf ball, a baseball, and a tennis ball." (Here, "golf ball," "baseball," and "tennis ball" are all specific types of balls.)