Concatenate works only with single cell values. You can use
=CONCATENATE(A1," ",B1)
However, you cannot do something like
=CONCATENATE(A1:B10)
CONCATENATE doesn't work in array functions. Indeed, there is really
no reason to ever use the CONCATENATE function. You can do the same
thing with less typing by using the & operator:
=A1&" "&B1
Cordially,
Chip Pearson
Microsoft MVP
Excel Product Group
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)