[NTG-context] Another question to structured trees for linguistics

Hi everybody! I have another question to this thread: if I need a structured tree for lingustics, i mean a structured tree with senteces, can I use also mp-trees? I ask, because at Ctan I found a package called "qtrees". So in this package ist called \Tree and then there comes the following: [.S This [.VP [.V is ]\roof{a simple tree}.NP ] ] for example . Or how would I write it in metapost? Can somebody help me? Uschi