frog software package provides tagger and parser for natural languages (runtime), 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 frog
frog is installed in your system.
Make ensure the frog package were installed using the commands given below,
$ sudo dpkg-query -l | grep frog *
You will get with frog package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Science |
| Package | frog |
| Version | 0.13.5-1 |
| Description | tagger and parser for natural languages (runtime) |
| Sub Section | Science |