"To improve students' spoken Engpsh" 用英语可以说成 "To enhance students' oral Engpsh proficiency"。
来源："To improve" 意为 "提高"，"enhance" 意为 "增强"，"oral" 意为 "口语"，"proficiency" 意为 "熟练程度"。
例句：
"The school is implementing a new program to enhance students' oral Engpsh proficiency." (学校正在实施一个新的项目来增强学生的口语英语熟练程度。)
"The teacher is always looking for ways to improve her students' spoken Engpsh." (老师总是在寻找提高学生口语英语的方法。)
"Speaking Engpsh in class is one way to enhance students' oral Engpsh proficiency." (在课堂上用英语交流是增强学生口语英语熟练程度的一种方式。)