假如陈述部分含有 hardly, seldom, scarcely 等否定副词时，后面的反意疑问句要用一定式。如：
I’ve never let you down, have I?
She’s never had her appendix out, has she?
You seldom see that sort of thing these days, do you?
She can scarcely speak the language, can she?
但假如陈述部分含有副词 too（太）呢？反意疑问句是要用一定式还是不是定式。如：
He is too old, ______ he?
He is too old to do the work, _______ he?
当一个句子中有never, seldom, hardly, few, little, barely, scarcely, nothing, none, rarely, no, not, no one, none, nobody, neither...等否定词时，句子无论是在乎义上还是在形式上都是相反的，如此的句子才是不是定句。这个时候，假如后面接附加疑问句，一般要用一定形式。而too并非一个否定词，too...to 结构有时只不过在乎义上表达否定，而在形式上仍是一定的。所以，附加疑问句要用否定式。即：
He is too old, isnt he?
He is too old to do the work, isnt he?
▲另外，too...to 结构并不一直表示否定意义的，也可表一定的意义。如：
He was too eager to succeed.他太急功近利。
Your arguments are too easy to be cut down.你的论点一驳即倒。
We are all too pleased to listen to the opinions of other.大家很乐意听其他人的建议。
