The emergences of the aspect suffixes le (perfective) and zhe (progressive) were epoch-marking events in the history of Chinese grammar, and their development processes should be seriously studied. This chapter explains the reasons why they emerged at the time they did. Two closely related questions need to be answered: what factors in the earlier grammatical system blocked aspect suffixes from grammaticalizing? What changes in the grammar at the time made it possible for them to come into existence? The motivation and mechanism for their development involves two factors: (a) the overall change of the grammatical system at the time and (b) the concrete grammaticalization process of each aspect suffix.

This unit introduces students to the future tense, and also to the present continuous. Along with the latter, the gerund (which is needed for the present continuous) is explained. The regular and irregular forms of the future are presented. A comparison is made of English and Spanish ways of expressing the future. Both can use a future tense to express a supposition or probability, but where English might use a present continuous to describe a future event, Spanish needs a future tense. The present continuous and the gerund are less common in Spanish, particularly the gerund, which may not be used as an adjective or a noun, but is principally used as an adverb. The new tenses enable students to describe future plans and arrangements, giving or refusing invitations. These uses are supplemented by information as to how to write letters or use the telephone, and also by explanation of the useful verb pensar.

This unit introduces students to the future tense, and also to the present continuous. Along with the latter, the gerund (which is needed for the present continuous) is explained. The regular and irregular forms of the future are presented. A comparison is made of English and Spanish ways of expressing the future. Both can use a future tense to express a supposition or probability, but where English might use a present continuous to describe a future event, Spanish needs a future tense. The present continuous and the gerund are less common in Spanish, particularly the gerund, which may not be used as an adjective or a noun, but is principally used as an adverb. The new tenses enable students to describe future plans and arrangements, giving or refusing invitations. These uses are supplemented by information as to how to write letters or use the telephone, and also by explanation of the useful verb pensar.