Combustion engine and method for operating a combustion engine

The method serves to operate an internal combustion engine (1), which can be used in particular in automobiles, which has at least one piston (10), a reciprocating piston or a rotary piston, by means of which a fuel-air mixture (G+S) is compressed in a combustion chamber (19) and subsequently ignited, wherein a gaseous first fuel (G) and air (S) can be introduced into the combustion chamber (19) mixed or unmixed in order to provide the fuel-air mixture (G+S). According to the invention, a second fuel (D) is supplied to the compressed fuel-air mixture (G+S) present in the combustion chamber (19), which second fuel (D) has a higher ignition tendency than the first fuel (G) and by means of which the fuel-air mixture (G+S) supplemented with the second fuel (D) is ignited.