There is no or there was no

Question

I read a sentence in an exam:

There is no child who did not bring his parents to the picnic.

I think that the sentence does not have tense-agreement. Why is is used instead of was? Please explain it to me.

Answer 1

There's slightly different meanings between using "was" and "is" here.

Imagine you're either still at the picnic or all the children from the picnic are present.

You ask your friend to make sure all the children brought their parents. The children are all still around. He confirms "There is no child who did not bring his parents".

The picnic is over, your friend was keeping track of the children's parents, and the children are gone. You ask your friend if all the children brought their parents. He confirms "There was no child who did not bring his parents"

The difference between the two is that in the first example, the children are all still here around you in the present. In the second example the children are no longer here, they are gone. If the children are still around you, you use "is". If the children have left, than you use "was". The "to be" verb is modifying "There".

There is no verbal relation between the children being present and them bringing their parents, so the fact that they brought their parents does not need to agree with their current presence.

Compare:

"There are people at the event who fought in the war" "There were people at the event who fought in the war"

The fact that they fought in the war is not relevant to their current location. If they are still present at the event, you say "There are". If they are no longer at the event then you say "There were".