--- a/debian-apt.rst	Wed Jan 23 20:39:31 2019 +0200
+++ b/debian-apt.rst	Sun Jan 27 03:11:05 2019 +0200
@@ -232,8 +232,23 @@
   $ gpg --export 9AA38DCD55BE302B | sudo apt-key add -
   OK
 
-Install build dependency for package.
-=====================================
+List packages
+=============
+
+List all known packages::
+
+  apt list
+
+List installed packages::
+
+  apt list --installed
+
+List upgradable packages::
+
+  apt list --upgradable
+
+Install build dependency for package
+====================================
 ::
 
   $ apt-get install build-essential    # install dev LIBC and GCC C/C++