I work in an I.T. company and I was assigned to work with a lazy guy who needs constant baby sitting. For instance, yesterday he asked me to go to his desk because he could not type the "@" symbol.
In Spanish we have an idiom that says : "He got drown in a glass of water". Which means he gets stuck and in minor or dumb things.
What's the most similar idiom in English?
You can say he's 'high-maintenance'. https://www.macmillanthesaurus.com/high-maintenance
The English language has numerous idioms comparable to 'he would drown in a glass of water'¹. Some examples:
They're not the sharpest knife in the drawer.
They're not the brightest light in the harbor.
They're a few screws short of a hardware store.
They're about as sharp as a marble.
Their elevator doesn't go all the way to the top floor.
Their lights are on but nobody's home.
Their IQ would make a good golf score.
They couldn't pour water out of a boot that had instructions on
the heel.
Their driveway doesn't quite reach the road.
Their antenna doesn't pick up all the channels.
They're proof that evolution is reversible.
They're running on 3 cylinders.
Their engine is running but nobody is behind the wheel.
If you gave them a penny for their thoughts, you'd get
change.
It's hard to believe they beat out 100 million other
spermatozoa.
If evolution was an experiment, their ancestors were in the
control group.
They would be unarmed in a battle of wits.
They're not rowing with both oars.
Their phone's connected but there's no dial tone.
They're an open book but the pages are blank.
If they had a brain they'd be on the floor playing with it.
If brains were dynamite, they couldn't blow their nose.
If they were any slower they'd need to be watered once a
week.
They couldn't hit the floor if they fell on it.
Some of those were shamelessly stolen from (and there's more at) the Not Too Bright list.
¹ Your original example would seem to have an international circulation as I've heard it in EN-CA at least.
