I have a dual boot of Debian 8.8 LXDE and one of the most recent releases of Ubuntu. (I don't know number release). I have grub boot loader installed. Can I remove Ubuntu from the hard drive and Grub and combine the partition. Please help.
Backup whatever you might need from both installations (when changing partitions, things can go badly wrong). If grub was last installed from Ubuntu, reinstall grub from the Debian side. You may then remove the files from the Ubuntu partition and mount it on the Debian side (a home data partition for instance). If the Ubuntu partition is after the Debian partition (so the Debian partition will be expanded by moving its end), you may use gparted to delete the Ubuntu partiton and increase the Debian one. I think this may be done on a running system, and the filesystem will be increased to fill the bigger partition (with gparted, not something else). If you need to expand the Debian partition from the beginning, do that off-line (from a live install media for instance). The beginning expansion might be done with a move (of the whole partition), followed by a resize.
The "Tip" under item 1 of "Resizing a Partition" of the gparted manual, gparted manual indicates support for growing some online partitions.