Portuguese
In Portuguese, contractions are common and much more numerous than those in Spanish. Several prepositions regularly contract with certain articles and pronouns. For instance, de (of) and por (by; formerly per) combine with the definite articles o and a (masculine and feminine forms of "the" respectively), producing do, da (of the), pelo, pela (by the). The preposition de contracts with the pronouns ele and ela (he, she), producing dele, dela (his, her). In addition, some verb forms contract with enclitic object pronouns: e.g., the verb amar (to love) combines with the pronoun a (her), giving amá-la (to love her). See a list at Wikipedia in Portuguese: List of contracted prepositions.
Read more about this topic: Contraction (grammar)