The functions of なら are "contrast" and "limitation".

さしみ　を　たべたことが　あります　か。

Have you ever eaten sashimi before?

すし　なら　たべたことが　あります。

I have never eaten sashimi, but I have eaten sushi.

にく　は　たべられます　か。

Can you eat meats?

とりにく　なら　たべられます。

I can eat chickens, but I can not eat other kind of meats.

おさけ　は　すきです　か。

Do you like alcohol?

ビール　なら　すきです。

I like beer, but I don't like the other kind of alcohol so much.

References:

How to describe your experience

https://anchor.fm/yuya-sato/episodes/How-to-describe-your-experience-eog5ti

Potential Verbs #1

https://anchor.fm/yuya-sato/episodes/Potential-Verbs-1-eoqaoi

Potential Verbs #2

https://anchor.fm/yuya-sato/episodes/Potential-Verbs-2-eorp21

Introduction of Question Sentences

https://anchor.fm/yuya-sato/episodes/Introduction-of-Question-Sentences-emmh81

X likes Y / X dislikes Y

https://anchor.fm/yuya-sato/episodes/X-likes-Y--X-dislikes-Y-encubj

Instagram:

https://www.instagram.com/yuyaman1986