In order to successfully compile KVocTrain, you need the KDE libraries as well as the Qt™ C++ library. All required libraries can be found on ftp.kde.org/pub/kde/.
KVocTrain is tested with KDE 3.0 and Qt™ 3.0. It should also basically run under KDE 2.x and Qt™ 2.x if compiled accordingly but I can't promise.