动词不定式可用作独立成分，用来修饰整个句子，常见的有：
to begin with
to tell the truth
to make a long story short
so to speak
to be brief/exact/frank/honest
to say nothing of（姑且不说）
to say the least（至少可以这么说）
以上所列短语均为口语中常用短语。请同学们牢记！
a. To begin with, on behalf of（代表） all of your American guests,I wish to thank you for the incomparable（无可比拟的） hospitality.
首先，我谨代表你们的所有美国客人向你们表示感谢，感谢你们无可比拟的盛情款待。（尼克松总统1972年访华时的祝酒词开篇）
b. —You’re in pretty lousy mood, huh?
—To say the least.
c. I have a point there, to say the least.
d. To make a long story short, he is in hospital now.