Can capacitors amplify signals?
I havent heard of amplification using capacitors. wish to know how
  does it do and can we find the frequency response of amplification
  using capacitors


It depends on your definition of "amplifier". Wikipedia defines it like this: -


  An amplifier, electronic amplifier or (informally) amp is an
  electronic device that can increase the power of a signal (a
  time-varying voltage or current). It is a two-port electronic circuit
  that uses electric power from a power supply to increase the amplitude
  of a signal applied to its input terminals, producing a proportionally
  greater amplitude signal at its output. The amount of amplification
  provided by an amplifier is measured by its gain: the ratio of output
  voltage, current, or power to input. An amplifier is a circuit that
  has a power gain greater than one.


It is unambiguous in stating that the power gain is greater than 1 but this is just one definition. If you took a definition of an amplifier as a device that increased the voltage of a signal then you could argue that a transformer is an amplifier. You could also argue that an RLC filter was also an amplifier because it can provide significant voltage gain such as in this tuned circuit: -



Picture source.

At resonance the voltage amplification is 20 dB or a gain of 10. There is of course no power gain because there is no "extra" power source that can provide power.