I AM PLAYING TENNIS WITH MY BROTHER ON SUNDAY

Please state your exact question.

=)

I'll take a guess at what you're asking, but first, a couple of other things:

1. When you type in all-caps, two things happen:
~~it's harder to read
and
~~it's the online equivalent to SHOUTING.
Please just type in regular mode, not with the Caps Lock feature turned on. Thanks.

2. Be sure to put a period (or other appropriate end punctuation) at the end of every sentence.

The verb in that sentence is known as first person, singular, present progressive.
http://grammar.ccc.commnet.edu/grammar/progressive.htm

=)

That's great! Playing tennis can be a fun way to spend time with your brother. Is there anything specific you would like to know or discuss about playing tennis?