Mary (`m / `s) swimming.
is
I (`s / `m) walking to school.
am
The dog (`s / `re) chasing the cat.
is
The children (`re / `s) watching TV.
are
We (`s / `re) having lunch.
are
Bob (`s / `re) eating an apple.
is
They (`re / `m) playing the quitar.
are
The cat / swim
The cat is swimming.
They / play football.
They are playing football.
He / run.
He is running.
It / jump.
It is jumping.
I / eat.
I am eating.
We / read.
We are reading.
The phone / ring.
The phone is ringing.
They / cook.
They are cooking.
