THERE IS
Many times I get wrong when needing to use THERE IS alongside modals. For instance, is it correct to say:
THERE MUST BE A RABBIT UNDER THE TABLE
THERE COULD BE A THIEF WAITING FOR US AT HOME
THERE SHOULD BE A GUIDE MAN AT THE AIRPORT GATE

Many thanks in advance

Question

THERE IS
Many times I get wrong when needing to use THERE IS alongside modals. For instance, is it correct to say:
THERE MUST BE A RABBIT UNDER THE TABLE
THERE COULD BE A THIEF WAITING FOR US AT HOME
THERE SHOULD BE A GUIDE MAN AT THE AIRPORT GATE

Many thanks in advance

Answer

Yes, those verb forms are all fine. It should be 'guide' rather than 'guide man', but otherwise your sentences are perfect.