The Continuous Tense

According to Wikipedia:
In Spanish grammars, continuous tenses are not formally recognized as in English. Although the imperfect expresses a continuity compared to the perfect (e.g., te esperaba ["I was waiting for you"]), the continuity of an action is usually expressed by a verbal periphrasis (perífrasis verbal), as in estoy leyendo ("I am reading"). However, one can also say sigo leyendo ("I am still reading"), voy leyendo ("I am slowly but surely reading"), ando leyendo ("I am going around reading"), and others.