fg

From Initq

fg is a Unix job control command that resumes the execution of a suspended process in the foreground with its standard input and output streams redirected to the user's terminal. fg is a required to be included in order to POSIX compliant.
If you have a job running you can do Ctrl-Z to pause it and then you can use fg to bring it back in the forward ground. If you have severl jobs suspended then use the jobs command to find out the job number and use fg <num> to bring it in the forward ground.