Help with my Student!

I need a help. I don't know what to do with one of my students. I teach English Language to the last ranked class in the school. They are the seven years old.

I don't know what to do to one of them. He is very very slow. His writings are so bad. He doesn't concentrate in class or focus even though I've asked him every single time to take his chair and position it in front of me directly.

I even go to the extend, asking him to come 2 hours early than school time (I came early too just for him) and taught him personally. Basically all what I taught him was the next week's final exam. It took us all those 2 hours to make him understand and memorize 13 words. YEAH. 2 hours and just 13 words. I'm fine with that though, at least, there's progression. But I was so sad because the first class after that was his. I thought, he would've memorized what I just taught less than an hour before but he basically just answered wrongly to all the same questions I gave in class.

I really don't know how to save this child anymore. I'm losing my way. I know he can be saved but I just don't know how T.T

Help please? Any suggestion?

If it is clear it shouldn't be happening, that they're quite under the average, consider summoning their parents, try and see if there's a specific reason why it's going on

Do you think you'll get a better result of them if they dedicated about 30 minutes of their day to review what they learnt that day, at home?

Perhaps a different learning style? I remember learning spanish words when I was little, and it was through association. For example:

Bear = oso. The bear is o so scary!!!
Bad = malo. Eww the mashmellow tastes bad.

To this day the only spanish phrase I remember is el oso es malo!

That's a tough one, is this exclusively speaking?

What level is he? I teach B1/B2/C1/C2

Honestly, if he is lower level all I can recommend is repetition. Just go over and over and over and over.

Don't think he needs 'saving' some children just struggle to concentrate and learn in school you just need to take your time with them maybe working with them for 2 hours is too long at once maybe they need maybe just 30mins or and hour at a time.

I did two hours because I can't really find any other time. I did another two hours yesterday and he seems to get it after the last one. At least he's faster to catch up now. Today is the examination. I truly wish he can answer well. I really do wish to help him more but I am only substituting for a month and I almost come to the end. T.T