Android Question

How can i increase my internal memory

Generally not possible as the memory chips are soldered to the motherboard and there are no expansion slots. You are stuck with the phone as it left the factory.

If you root the phone it may be possible to make the phone use a partition on the removeable sdcard as if it were internal storage, but it depends on what custom software exists for your particular phone.

If no suitable custom ROM exists for the phone, you can often use the app Link2SD to extend app storage onto a partition as Roger describes. But this still requires that the phone is rooted.