Welcome to the forums premanand! :hi:
The infinitive verb "to exist" is conjugated as follows:
I exist/we exist
you exist/you all exist
he exists/they exist
she exists/they exist
it exists/they exist
As you can see, in English, it is usually the third person singular that puts a final "s" on the verb. The other conjugations leave it off.
I live/we live
you live/you all live
he lives/they live
she lives/they live
it lives/they live
I run/we run
you run/you all run
he runs/they run
I cook/we cook
you cook/you cook
he cooks/they cook
I eat/we eat
you eat/you eat
he eats/they eat
We do have irregular verbs that conjugate differently, and still it is the third person singular which is the odd conjugation.
I go/we go
you go/you go
he goes/they go
I do/we do
you do/you all do
she does/they do
I have/we have
you have/you have
it has/they have
Do you see the pattern? In some of the second person plural conjugations I wrote "you all" to indicate that it is a plural. The fact is that when talking to a group of people you can either say, "You all are to go to . . ." or "You are to go to . . ." The "all" can be used or omitted. It's personal preference.
Have a pleasant day!
Sweet Momma Sue :usa