[color=indigo]1-I wouldn’t advise you to go to certain places on this island.
I think this sentence would usually mean:
[color=indigo]a-There are certain place on this island I would not advise you to go to. All the other places are fine.
But can’t it be used in two other contexts?
Are the following acceptable:
[color=darkred]2-I wouldn’t advise you to go to certain places on this island. All of it should be visited.
[color=blue]3-I wouldn’t advise you to go to certain places on this island. None of it should be visited.
In the cases of 2 and 3 then your original phrase would not be used.
For 2 the phrase would be similar to:
I would advise you to visit the whole island.
The negative form in any form, including this:
I wouldn’t advise you to only visit some of the places on this island.
would be avoided.
For 3 the phrase would be similar to:
I wouldn’t advise you to visit anywhere on this island.
I would advise you to avoide everywhere on this island.
Your original phrase only really carries the meaning you attribute to it — that there are some places to avoid.
Thank you very much Beeesneees for all your kind and detailed replies.
Can’t 2 and 3 be used in a very special case, ie. when one is contradicting something that has been said beforehand?
John: We were advised to go to certain places on this island.
[color=darkred]Harry: I wouldn’t advise you to go to certain places on this island. All of it should be visited. (1)
or:
[color=blue]Harry: I wouldn’t advise you to go to certain places on this island. None of it should be visited. (2)
These would not be independent sentences, as they are repeating something that has been already said.