As a variant of CFGs, dependency grammars (DGs) also enjoy wide popularity. The difference from CFGs is that hierarchical grouping is achieved by directly subordinating words to words (allowing for multiple dependents of a head word), rather than phrases to phrases. For example, in the sentence of figure 1 we would treat Thetis and mortal as dependents of loves, using dependency links labeled subj and obj respectively, and the determiner a would in turn be a dependent of mortal, via a dependency link mod (for modifier). Projective dependency grammars are ones with no crossing dependencies (so that the descendants of a node form a continuous text segment), and these generate the same languages as CFGs. Significantly, mildly non-projective dependency grammars, allowing a head word to dominate two separated blocks, provide the same generative capacity as the previously mentioned mildly context-sensitive frameworks that are needed for some languages (Kuhlmann 2013).