car won't start. battery okay and sound of trying to start heard, but doesn't. on 2008 Suzuki Grand Vitara

The car worked fine last night and today it would not start for my husband.

Asked by for the 2008 Suzuki Grand Vitara
poss battery or did he leave something on and battery is low volts
2 more answers
I take it that it turns over if so then I would check fuel pressure and for spark
How do you know your battery is good?