skkdic-expr2: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/skkdic-expr2 - from package: skktools

You may install the required package with command apt-get install {package}

Error in other languages:
skkdic-expr2: bevel nie gevind nie
skkdic-expr2: comandă negăsită
skkdic-expr2: comando não encontrado
skkdic-expr2: commande introuvable
skkdic-expr2: command not found
skkdic-expr2: käsku ei ole
skkdic-expr2: không tìm thấy lệnh
skkdic-expr2: komanda nerasta
skkdic-expr2: Kommando nicht gefunden.
skkdic-expr2: kommandot finns inte
skkdic-expr2: komut yok
skkdic-expr2: nie znaleziono polecenia
skkdic-expr2: níor aimsíodh an t-ordú
skkdic-expr2: no se encontró la orden
skkdic-expr2: no s'ha trobat l'ordre
skkdic-expr2: opdracht niet gevonden
skkdic-expr2: parancs nem található
skkdic-expr2: perintah tidak ditemukan
skkdic-expr2: príkaz nenájdený
skkdic-expr2: příkaz nenalezen
skkdic-expr2: команда не найдена
skkdic-expr2: командата не е открита
skkdic-expr2: 命令找不到
skkdic-expr2: コマンドが見つかりません