Complex sentence: A guitar amplifier (or guitar amp) is an electronic amplifier designed to make the signal of an electric or acoustic guitar louder so that it will produce sound through a loudspeaker and modify the tone by emphasizing or de-emphasizing certain frequencies and adding electronic effects.
Split into simpler sentences: A guitar amplifier (or guitar amp) is an electronic amplifier designed to make the signal of an electric or acoustic guitar louder so that it will produce sound through a loudspeaker. Guitar amplifiers also modify the instrument's tone by emphasizing or de-emphasizing certain frequencies and adding electronic effects.