How do I start saving on SD card My phone kept saying device out of space  so I bought an SD card and inserted it into the phone but my phone is still saying the same thing. How do I start using SD card please, thank you.
The storage is still calculated separately (internal VS. external), so internal is still low on space, hence the alert.

At this moment, use a file explorer to go through your internal storage and see what's hogging space (music? video? installation files you forgot to delete?), and move anything necessary to the SD card. For some phones you can also go to Settings-Apps to move some installed apps to the card.

If the problem persists, please post screenshots of your storage details both in Settings-Storage and under Settings-Apps.