I’m starting a new job. My new boss is from an East European country, and has accented characters in her name (ž to be exact). I would like to be able to use the correct diacritics when writing her name. Easy on my Mac (long key press to show all diacritics for a letter), but less so on my Android phone.
While the android language setting is set to English (UK) this character isn’t available via a long press (as it would be for è, â and ç). To make it available, I need to add a language that includes it (Croatian for example).
Here’s how:
- Settings > Language and input
- Virtual keyboard
- Gboard
- Languages
- Turn off use system locale to allow selection of multiple languages
- Enable your home language and the additional language that has the characters you need.
Now the accented options are available on a long press of the parent letter.
I also noticed that the gboard suggestions now includes the accented characters when before it didn’t.
Fixed.
dunxd.com 
I came across your post while searching how to accomplish exactly the same thing. However, I got stuck on the “Turn off use system locale to allow selection of multiple languages” step. I can’t seem to find any such option in my language settings, not in the Gboard settings.
I am using Samsung Galaxy S8 so maybe they changed something…
Actually managed to solve this by adding Esperanto keyboard in multi-language mode with English. Now it has all the characters I’ll ever need (čćšž), and many I’ll never use, like ŵ and ķ 🙂
As an added bonus, I can use old English eð and þorn (except that “þ” is bound to the “y” key).
I didn’t see this option in my phone (Android 9). I added Esperanto keyboard with QWERY Layout. it works for me!
I also came across thy post and I need help in how do I add this letter to my long press letter s in my Google keyboard: the ſ. It is called “long/medial position s”
You need to work out which language includes this character and set up Google keyboard in that language. Looking at https://en.wikipedia.org/wiki/Long_s it looks like it may be in Norwegian, Finnish and maybe Turkish languages but I can’t say for sure.
Thank you Arusha and Nomæd.
How do I turn up the acute accent on Android phone
Not all characters are represented with long press on Gboard. It is disgusting.