在用be設問時,v要+ing,是不是用了Gerund呢?

No a gerund...

it's just a simple preent continuous tense.

e.g. I am eating. (continusous tense)
I enjoy eating (gerund)

Both of the above two sentences consist of two verb, "are" + "eating" & "enjoy" + "eating". The former one is using the "verb to be". It is the fundamental structure of a present continuous tense.

c.f. "enjoy" is a main verb. It is grammerical incorrect to have two main verb in one sentence. Therefore, the other verb "eat" need to change either to the form of infinite or gerund to make the sentence correct. In case, a gerund will be used for the verb "enjoy".


Referring to your question, your sentence involve the verb "are/were", a "verb to be". Therefore, it is a continuous tense which represent a particular event is taking place at certain moment.

eat, drink, swim, run...等等都是動詞.
如:
I want to eat banana. ( 我想吃香蕉. )
I want to drink lemon tea. (我想飲檸檬荼)
I want to go to swim on Sunday. (星期日, 我想去游水)
My brother runs very fast. ( 我的弟弟跑步很快)

但當動詞想用作名詞是, 就成為:

Eating can make me feel happier. ( 吃東西能令我快樂)
Drinking too much is not good for health. (飲酒太多對身體有害 )
I enjoy swimming very much in Summer. (在夏天，我十分享受游泳)
Running is my favourite sport. (跑步是我最喜愛的運動)

這些都是動詞作名詞用，So Gerund 中文是 " 動名詞 " , 即動詞的名詞。
這些都是一些簡易例子,希望你明白啦!