His memory is going.
His hearing is going.
I think the above means improving. Maybe his memory was weak.
A doctor gave him some drugs. Now it is better.
It's the opposite.
It's going = deterioriating.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Thank you all.
If the man is ill and the doctor says the illness will turn to worse, it is possible to say his health is deteriroting.
Do you say even 'his health is going'?
This is not possible in Russian.
***** NOT A TEACHER *****
Oh, yes, Tina, "to go" in English can mean to deteriorate, leave, go away, disappear, etc.
This is a family friendly website, but -- if I am careful -- I may be allowed to tell you this:
Some American men always get a big laugh if they say something like this to an individual or a group:
"Sorry if I can't hear you very well. My hearing is the second thing that has gone."
(P.S. The first thing refers to his virility.)
Mr. / Ms. Moderator: If I have crossed the line, I shall humbly accept deletion and suspend myself for one week.
Is it fine to use for clothes, machineries, etc?
The car is old and starting to go. [ Maybe you experience problems very often]
My trousers are old. They have started to go at the buttocks.
(I don't know whether you can use the words 'to go' for clothes and machineries.)