“You can hear the gas coming out when you turn the knob, but it doesn't ignite.”
Your kitchen stove doesn't work. You call your landlord to fix it. You explain the problem to him like this
You can hear the gas coming out when you turn the knob, but it doesn't ignite.
"Gas" can mean a few different things in American English:
- Gasoline, which you put in your car to fuel it.
- Gas, which is kind of like air. Air is a kind of gas. The Helium inside a balloon is another kind of gas. "Gas" contrasts with "liquid" and "solid".
- Natural gas is a kind of gas (definition #2) that can be burned for heat or energy. This is what people sometimes use in their stoves.
A "knob" is something that you turn in order to control something. Some examples of "knobs" include:
- a doorknob
- the volume knob on a radio
- a knob to turn a lamp on and off
To "ignite" means to catch on fire. The word "ignite" describes just the moment when something first begins to burn. For example, a match "ignites" when you strike it.
You can use "ignite in the pattern "(someone) ignites (something):
She ignited each of the candles, one by one.
But you shouldn't use "ignite" without an object when talking about people, unless the people themselves are burning!