"有" 在台灣國語 及 閩南 客家方言中的用法 請見以下 http://ling.nthu.edu.tw/faculty/wttsai/papers/Syntax%20in%20Chinese/taiwan_gouyu_han_fangyian_zhong_de_you%20(2002).pdf "哪里有卖橄榄油?" 是一種減省的表達方式 即 "哪裡有賣橄欖油的商店?" 賣東西的地方就是商店 (店家 / 賣場) 不言而喻 故略去 "的商店" 同理 "哪裡有賣牛肉麵?" 即是 "哪裡有賣牛肉麵的餐館?" 賣牛肉麵的地方就是餐館 故略去"的餐館"

"I was told to avoid using the 有+verb construction" i gotta ask you who told ya that, :-p? 我有吃饭 is not correct, because you need to use 过 in this sentence, since 吃 is used as a transitive verb. However 你有吃 also makes perfect sense in cases where 吃 is used as intransitive verb, for example, if someone asks you: 你有吃吗？you can say 我有吃. you are not suppose to break 有 apart from 哪里有, its a phrase which means: is/are there. 哪里有卖橄榄油的 is correct, but it is uncertain whether you are talking about people who sell olive oil or shops. Its ok to omit the noun after 的, but its just not very clear, in most case it doesnt matter. 我是卖橄榄油的 is fine, and you are right that 人 can be omitted here, since "I" is used.

【哪里有卖橄榄油】you can take 卖橄榄油 as 【selling olive】。 but this is surely an over-abbreviated sentence。at least it should be 【哪里有卖橄榄油的】

It's a standard way of asking "Where can I buy olive oil?" but the literal meaning should be more like "Where is there olive oil for sale/to sell?" as in Lao Kau's comment or "Where is the selling of olive oil?" or some such.

So what does it mean?