Tower Controller reported student pilot failed to follow control instructions in the traffic pattern resulted in an NMAC. Controller also stated that a language barrier could have added to misunderstanding of control instructions.

Narrative

Aircraft X was a student solo pilot who called up for pattern work. I already had 4 in the pattern on our traffic pattern runway (RWYXX) so I decided to give them right traffic for RWY XY to keep them isolated and give them more space. When they entered the downwind I told them to extend downwind to follow a king air on a 4 mile final. I noticed the PA28 drifting towards final and instructed them to widen out to the east and told them about the king air traffic. They continued as heading the same direction they were into the traffic on final. I issued multiple more traffic calls and instructions to widen out to the east; including at one point telling them to turn left now. At this point; the king air pilot had reported the PA28 in sight and made maneuvers to avoid. The king air pilot reported a near miss; and was able to continue inbound to land safely. The PA28 student pilot never seemed to grasp what was going on; and when I told them to turn inbound to land on runway XY for a full stop they asked if they could get runway XX for pattern work. I told them no; that they had failed to listen to instruction; and gave them a full stop back to parking. The brasher warning was given to the pilot on ground control as they taxied back to parking.I thought by giving the student pilot an empty traffic pattern; they would have been able to fly that with no issue. There is a language barrier with that particular school; and I'm not sure the student pilot understood the instructions that were being issued. Instead of telling him to widen out to the east; I could have been more clear and told them to turn left to avoid the traffic instead of a cardinal direction.