医生说必须住院英语怎么说

"The doctor says you must be hospitalized" 医生说你必须住院
The sentence you provided is a direct translation of the original sentence. The use of "The doctor says" indicates that the statement is coming from the doctor and is something that they believe is necessary. The word "hospitalized" is used to indicate that the person must stay in a hospital for medical treatment.
Some example sentences:
"The doctor says you must be hospitalized for observation." 医生说你必须住院观察。
"The doctor says it's necessary for you to be hospitalized." 医生说你必须住院。
"The doctor says that you will require hospitalization." 医生说你需要住院。
在英语里, "hospitalization" 是动词"to hospitalize"的名词形式,表示将某人住进医院的行为。