Install gir1.2-gtkspell3-3.0 by entering the following commands in the terminal:
sudo apt update sudo apt install gir1.2-gtkspell3-3.0
Description:
GObject introspection data for the GtkSpell library
This package contains introspection data for GtkSpell, a spell-checking library for GTK+. They can be used to generate dynamic bindings. . GtkSpell provides Microsoft Word/OS X-style highlighting of misspelled words in a GtkTextView widget. Right-clicking a misspelled word pops up a menu of suggested replacements.
Homepage: http://gtkspell.sourceforge.net/
Version: 3.0.9-2
Section: universe/introspection