The sending pipe of my air compressor is broken. It is a copper pipe, hard pipe I believe. Can I replace that sending copper pipe with a soft one?
It depends on how much vibration there is. Copper is subject to metal fatigue, similar to when you bend a paper clip back and forth until it breaks. The same effect takes place on copper tubing, except it is softer than steel, so it tends to work harden or fatigue more easily than steel. (That is probably why your original tubing broke) You can replace it with copper tubing, but it isn't likely to last very long. But it would be an OK fix as a temporary repair.
