Hi, for some reason, my actual phone memory has started to get low? I copy all my apps onto my memory card as for some reason, they all go to the phone memory when downloaded and installed.

How can I tell why my phone memory is gradually getting smaller and smaller, and why?

I have an LG Optimus One (P500).

Thanks

Do you delete browser history. Also clear cache and data stored by apps. This will free ups surprising amount.

Even if you move apps to SD, some of the app will remain in phone memory. Also, upgrades will gradually reduce the amount of space available. Some apps use the phone regardless eg kindle paid books are held on the phone.
You can use app2sd app to move apps to SD and clear your cache in one go.