stemwords: command not found

Have You tried accessing the binary with the full path?

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/stemwords - from package: libstemmer-tools

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