是prefer to do 还是prefer to doing突然之间发现好多小语法都不记得了额

是prefer to do 还是prefer to doing
突然之间发现好多小语法都不记得了额

▲Prefer to do sth.宁愿做…,也不愿做….
①I preferred to stay behind rather than go with you .我宁愿留下来不愿和你们去.
②She preferred to write to him rather than telephone him .她宁愿给他写信也不愿给他打电话.