5. A system for identifying treelet translation pairs, from training data, for use in a machine translation system that translates a source language input into a target language output, the system comprising: a processor; a treelet pair extractor configured to access a corpus of pairs of aligned, parallel syntactic dependency structures, each pair including a source language dependency structure having nodes that represent lexical items, the nodes being aligned with nodes representing lexical items in a target language dependency structure; and the treelet pair extractor being further configured to enumerate sets of source nodes that are connected portions of the source language dependency structure as possible source treelets using the processor, the treelet pair extractor being configured to enumerate a plurality of possible source treelets of different sizes from the source language dependency structure, the size of each possible source treelet being indicated by a number of nodes contained in the possible source treelet.
5. A system for identifying treelet translation pairs, from training data, for use in a machine translation system that translates a source language input into a target language output, the system comprising: a processor; a treelet pair extractor configured to access a corpus of pairs of aligned, parallel syntactic dependency structures, each pair including a source language dependency structure having nodes that represent lexical items, the nodes being aligned with nodes representing lexical items in a target language dependency structure; and the treelet pair extractor being further configured to enumerate sets of source nodes that are connected portions of the source language dependency structure as possible source treelets using the processor, the treelet pair extractor being configured to enumerate a plurality of possible source treelets of different sizes from the source language dependency structure, the size of each possible source treelet being indicated by a number of nodes contained in the possible source treelet. 6. The system of claim 5 wherein each child node of a parent node is considered to be connected with other child nodes of the parent node, and extract well formed treelet translation pairs from the possible source treelets and corresponding aligned portions of the target language dependency structure.