1. how long - Adjective
2. how long - Adverb
Used literally: what length.
How long is that piece of string?
I don't know how long the Amazon River is.
Used literally: what duration.
How long is the flight?
How long is it to lunch?
how long
Used literally: for what duration.
How long have you lived in Chicago?
He won't tell me how long he is going to stay.
No matter how long you play rock n roll songs might change just as the balls are there, the rock balls. And that's what's important to us. Bon Scott
I don't take things for granted, because everything feels more fragile. It's made me wonder about mortality and how long you've got somebody in the world. I'm more fearful than I used to be. Maurice Gibb
The success of most things depends upon knowing how long it will take to succeed. Montesquieu
No matter how long the night, the day is sure to come. African Congo Proverb
No matter how long the winter, spring is sure to follow. Guinea Proverb
No matter how long the procession, it still ends up in church. Filipino Proverb