aspell-uk software package provides Ukrainian dictionary for GNU Aspell, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install aspell-uk
aspell-uk is installed in your system.
Make ensure the aspell-uk package were installed using the commands given below,
$ sudo dpkg-query -l | grep aspell-uk *
You will get with aspell-uk package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Text Processing |
| Package | aspell-uk |
| Version | 1.7.1-1 |
| Description | Ukrainian dictionary for GNU Aspell |
| Sub Section | Text |