difference between mend, repair, and fix

mend - (нөхөх, нөхөөс тавих, нөхөн сайжруулах)mend is used more for clothing
1 to repair a hole in a piece of clothing, etc.
mend something
      ---- He mended a rip in his pants.
2 to find a solution to a problem or disagreement
mend something
      ---- They tried to mend their differences.
repair - (засах, сэлбэх, засварлах) 1)Repair-refers more to the technical context of fixing something.. Repairing objects
2)'If a robot has a technical problem, it would cost the company so much money and time to repair it.'
1 to restore something that is broken, damaged, or torn to good condition
repair something
       ---- to repair a car/roof/road/television
       ---- It's almost 15 years old. It isn't worth having it repaired.
2 to say or do something in order to improve a bad or unpleasant situation
repair something
       ---- It was too late to repair the damage done to their relationship.
fix  - (тогтоох, засах, сэргээх) 1) Fix covers most of most meanings of repair. 2) fix is used when we want to put sth back into its original condition or restore a situation to its former state

1 to repair or correct something
fix something
        ---- The car won't start—can you fix it?
        ----- I've fixed the problem.
2 to decide on a date, a time, an amount, etc. for something
        ---- Has the date of the next meeting been fixed?
        ---- They fixed the rent at $600 a month.
The only difference between repair and fix is that 'repair' is slightly more formal, so you need use "repair"  in writing.

difference between mend, fix, and repair

• Not much difference, in my initial reaction. repair and fix are the most common, I think, in AmEng. I somehow have the feeling that mend is used more for clothing and, for some odd reason, for something more abstract [the conference seems to have mended relations between the two countries].

• Fix - is the most commonly used, because it's short and has a very wide meaning range - not only literally for repairing something, but also for attaching or mounting, sceuring. You can say "I'll fix that" for whatever is to be done. Repair and mend don't these alternative meanings. 
  
  Repair - a quite neutral and precise way to say you fixed something broken :-)
  Mend - is a quite old-fashioned verb, but means the same as "repair".

• In the UK, the word "mend" is still in common use, in all of the circumstances previously outlined.
  
  Only last week, my stereo music player stopped working and had to be mended. Of course, I took it to a "repair shop".
  
  In general, British socks are "darned" rather than "mended". This is a reference to the type of repair necessary to mend the hole.

• Repair-refers more to the technical context of fixing something.. Repairing objects (repairing a car, repairing damaged tissue in the body)
  
  Fix- This is more broader..You could fix a problem, an object, or a concept.
  
  Mend: Refers to healing something. Mending a broken bone, or a broken heart for that matter.

• 'repair' suggests bringing something out of whack back to its original state of functioning.
  'fix' suggests making something functional that is out of whack but not necessarily like new.
  'mend' suggests putting something back together that has been broken or torn.

• In general, fix is used when we want to put sth back into its original condition or restore a situation to its former state. Fix emphasizes the existence of a problem.                                                      Repair is often used when we refer to the actual components of the problem. Repair emphasizes damage to certain things.                                                                                                                  Mend is often used when referring to damage to clothes or fabric in general.

• Good answer, but about mend I have some differences. You're right that it's a word largely specialized to mean "repair clothing," but I'm not sure I'd call it old-fashioned. Would you really say "She fixed my sock? Or "he took out his needle and thread and fixed a split seam on my dress?" Well of course you wouldn't use the phrase "my dress" in any context most likely, but you get my point.
  
  As for other uses, you can mend relationships or "mend fences," and a doctor can mend an injured body, and a naughty person can mend his ways. Mend has an intransitive use that fix doesn't-- wounds mend, as do figurative injuries like broken hearts. A person can be "on the mend."
  
  As for repair, it tends to describe fixing things that are broken or malfunctioning(эгзэгтэй), but it has some of the same abstract(хийсвэр санаа) and figurative uses as mend. You can repair broken relations as well as appliances(гэр ахуйн хэрэгсэл) and such things that are "broke." Fix covers most of these meanings of repair, but it sounds a little informal when applied to intangible things that are "repaired," for example repairing the imbalance or the "rift" between people. We talk, for example, of reparations for things for which there is "no easy fix."
  
  As you pointed out, fix has a whole array of other meanings. "Fix bayonets" does not mean repair them. But in addition to being a more widely useful word, and more general, fix is also far more informal or colloquial. Where that factor is limiting, fix yields to a more specialized or technologically exact word-- like reconfigure, for example.

difference between repair and fix

• 'If something goes wrong with a robot, it would cost the company so much money and time to (fix / repair) it.'
  
  In this context which is better, 'fix' or 'repair'?
  
  Also I'd like to make it clear what is the difference between 'fix' and 'repair'.
  
  Thank you in advance.

• The only difference I sense is that 'repair' is slightly more formal, so I would recommend using that in writing.
  
  (They of course have other meanings that are not synonymous: 'repair to the sitting room'; 'fix a race'.)

• Both works, but to me, 'fix' sounds more fit in the particular sentence. It flows better in the sentence. I mean, try reading it aloud. Oh and I think it pairs better with 'something goes wrong' part of the sentence. (This is not a rule though, and it doesn't apply everywhere)

• 'If there is a technical problem with a robot, it would cost the company so much money and time to repair it.'
  
  or
  
  'If a robot has a technical problem, it would cost the company so much money and time to repair it.'
  
  I guess 'a technical problem' sounds more formal than 'something goes wrong with'