How do I troubleshoot my Vauxhall Corsa's engine not starting?

My Vauxhall Corsa's engine won't start. It's not a battery issue, but the engine just won't turn over. What could be causing this and how can I fix it?

First, check that all of your electrical connections are secure and clean. Sometimes a loose connection can prevent the engine from starting. If that doesn't solve the problem, it could be an issue with the starter motor or ignition switch.

Another common cause of an engine not starting is a faulty fuel pump. If you hear a whining noise when you turn the key, it's a sign that the fuel pump needs to be replaced.

One thing you can try is jumpstarting your car. This can help if the issue is with a weak battery. However, if you've already ruled out the battery as the problem, it's better to have a professional diagnose and fix the issue.