In the months leading up to their son's first words,在引导儿子说出第一个词的日子里

lead up to导致； 引导； 作为 ... 的准备；一直通往（某处）；为…做准备，为…铺路

A flight of steps led up to the house.

一段台阶向上通到了屋前。

Her kind words led up to a request for money.

她的好话为要钱的事打开了门路。

then over the next several months learned to slowly approximate the proper speech form.在接下来的几个月里经过学习逐渐向正确的表达方式靠拢

learn to学习

I must learn to snatch at every chance to meet him.

我必须学会抓住一切机会同他见面。

A mountaineer must learn to stand the gaff.

一个登山运动员必须学会吃苦。

speech form言语形式