If you can't execute commands without full pass to them :

E.g. shutdown, reboot, mtr:
Do next:
Edit your .bash_profile

$ vi .bash_profile

Change PATH line to this:

PATH=$PATH:$HOME/sbin:/usr/sbin:/usr/local/sbin:/sbin:.

 There should be export PATH in the end of file

To apply changes you have to do next thing:

. .bash_profile

Or try to logout and log back in.

.bash_profile file example:

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/sbin:/usr/sbin:/usr/local/sbin:/sbin:.

export PATH