In the field of computational linguistics, a morphological dictionary is a file that contains correspondences between surface form and lexical forms of words. Surface forms of words are those found in any text. The corresponding lexical form of a surface form is the lemma followed by grammatical information (for example the part of speech, gender and number). In English houses is a surface form of the noun house. The lexical form would be "house", noun, plural. There are two kinds of morphological dictionaries: aligned and non-aligned.