请求语法指点 I did write down the number on the paper.

这是英语中的强调,用do、 does、did，此句可翻译为：我确实曾……
英语中的强调:
在英语中可以用多种方法表示强调，现在小结如下：
1． 强调句型 It is /was …that /who…
I met John in the street yesterday afternoon.
It was I who/that met John in the street yesterday afternoon.
It was John who/that I met in the street yesterday afternoon
It was in the street that I met John yesterday afternoon.
It was yesterday afternoon that I met John in the street.
此句型可以强调主语，表语，宾语，状语等，强调人时可以用who或that其他则用that .此句型中也可以用情态动词.
2.用助动词do .does did.只用于陈述句（肯定句），祈使句，去掉后句意不变，不影响句意表达。
Do come to school early.
I do believe it .
3.倒装句，避免头重脚轻，把强调部分提前。
From the speaker on the wall comes from a doctor’ s voice ,“Good
morning!”
On one side of Tian an men Square stands the Great Hall of the
People