I have noticed that as far as question tags go, "isn't there?" is rarely used in conversations. Is it a common practice for native speakers to use "is there?" even for positive statements?
There's enough food for all of us, is there?
This is wrong based on the rule, but is this more likely to be used in conversational English than the one with "isn't there"?
Pope of the Dictionary.com Forum
There isn't enough food for all of us, is there?
There is enough for all of us, isn't there?
The two sentences above contain the standard question tags and they are used almost all the time.
Your suggested version is possible but only when someone is expressing disbelief.
John: There's enough food for all of us.
Tim: Are you sure?
John: Yes, just take a look in the kitchen.
Tim (a few minutes later): I just looked in the kitchen and I could only find two potatoes, a bag of rice and an onion.
John: That's right. That's what I bought.
Tim: Oh! So there's enough food for all of us, is there? You are totally wrong - there are twelve people. That amount of food is definitely not enough.
Thank you for the help.