In this study we will discuss our cross language text retrieval (CLIR) experiments with the Persian language at the ad hoc track at CLEF2008. Two teams from University of Tehran were involved in cross language text retrieval part of the track using two different CLIR approaches that are query translation and document translation. For query translation we used a method named Combinatorial Translation Probability (CTP) calculation for estimation of the translation probabilities. In the document translation part we used the Shiraz machine translation system for the translation of the documents into English. Then we created a Hybrid CLIR system by score-based merging of the two retrieval system results. In addition, in this study we investigate Ngrams and a light stemmer in our monolingual experiments.