apertium-it-ca software package provides virtual package provided by apertium-ca-it, 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 apertium-it-ca
apertium-it-ca is installed in your system.
Make ensure the apertium-it-ca package were installed using the commands given below,
$ sudo dpkg-query -l | grep apertium-it-ca*
You will get with apertium-it-ca package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Virtual packages |
| Package | apertium-it-ca |
| Version | |
| Description | virtual package provided by apertium-ca-it |
| Sub Section | Virtual |