The government agency requires all applicants to fill out duplicate
forms when filling a grant request and to put their social
security number on every form.
想要請問一下這邊的When是什麼詞性?
問了一位是說When當介系詞後面加Ving
如果When當連接詞後面接S加上V
另外一位的說法是說When通常是不能拿來當介系詞
說這邊的when是連接詞後面的filling是分詞構句??
兩位不同的說法???哪一方說法才是正確的~跪求文法達人