Microsoft designed the on-screen keyboard in Windows 10 with tablet users in mind. The large keys are easy to tap, autocorrect and text suggestion are built in and there's an emoji button. However, the default keyboard is missing special keys, such as function keys and a number row. If you prefer a full keyboard layout or just need to use it once in a while, here's how to access it.
To switch to the full keyboard layout, you have to turn the option on in Settings.
1. Open the Settings app. You can do this from the Start menu.
2. Click or tap Devices.
3. Click or tap Typing.
4. Toggle on "Add the standard keyboard layout as a touch keyboard option."
5. Now click or tap the keyboard icon in the taskbar.
If you don't see that icon, right-click or long-press on the taskbar and select "Show touch keyboard button."
6. Click or tap the keyboard button at the bottom right of the on-screen keyboard.
7. Select the standard keyboard icon. It's the right-most icon.
Now you'll have access to the Alt, function, tab, and other keys missing from the default touch keyboard. To switch back, head to that keyboard button again to change the layout.