這句子不怪。"It was fun getting to know her"是常見說法，你只是不熟悉這「特定」說法。"....是Getting to know her嗎？" -> Yes."虛主詞只有少數名詞搭配動名詞" -> (你列的 useles 是形容詞) 也因為這侷限於特定的搭配字眼/使用場合，所以一般文法書沒有列。(盲目的套的話出問題機率大)Swan的"Practical English Usage"有提到這用法。他的說明是" 'It' can be a preparatory subject for an -ingform. This is usually informal."幾個實例: It was nice seeing you.It's no use trying to explain.It's worth going to Wales if you have the time.