Despite sensitivity to the contextual demands of modification, children struggle with the production of complex NPs. What syntactic or semantic properties of NP embedding specifically introduce complexity? We compare production of definite descriptions with two modifiers that contrast in the attachment of the second modifier: sequential vs. recursive modification. Children (n = 71) produced overall fewer targets than adults (n = 13), but both groups found double nonrecursive modification (e.g. the plate with oranges under the table) much easier than recursive modification (e.g. the bird on the alligator in the water). We conclude that each embedding step introduces complexity beyond the elements and operations employed in the semantic composition of the structure, or the cyclic syntax that generates it.