1. A method for making merging decisions for a translation comprising: providing a translated text string in a target language of a source text string in a source language; with a merging system, outputting decisions on merging of pairs of words in the translated text string, the merging system comprising at least one of: a set of stored heuristics comprising at least a first heuristic by which two consecutive words in the string are considered for merging if an observed frequency f 1 of the two consecutive words as a closed compound word is larger than an observed frequency f 2 of the two consecutive words as a bigram, and a merging model trained on features associated with pairs of consecutive tokens of text strings in a training set and predetermined merging decisions for the pairs to predict merging decisions for a new translated text string; and outputting a translation in the target language based on the merging decisions for the translated text string.