done (or to do); es de esperar, it is to be hoped. See 395. 415.

6. For the position of subject and object pronouns of an infinitive see 245, 246, 253255. 416.

7. Al + infinitive expresses action coincident with that of the main verb and is practically equivalent to a temporal clause. al verme ( = cuando me vit.)) me saludO, on seeing me (when he saw me) he greeted me. 417.

8. Para + infinitive denotes purpose: lo hago para agradarles, I do it in order to please them. See 711. 418.

9. Por + infinitive usually expresses cause: por estar cans ado no fui, because of being tired

I did not go. This construction is often replaceable by the gerund: estando cansado no fui. See 453. Por + infinitive may also express purpose with effort involved: hare por venir. I shall try to come. See 711. 419.

io. De or a or al + infinitive may be used to replace an if-clause: de no estar seguro de eso (a no estar, or, al no estar, or, si no estuviese seguro de eso), no iria yo = if I were not sure of that, I would not go. 420.

1. The infinitive is directly dependent upon several verbs, such as desear, to desire, querer, to wish, want, deber, to be under obligation to, poder, to be able to, esperar, to hope, expect,

prometer, to promise, mandar, to order, etc.: deseo ir, I wish to go. 421.

1z. When an infinitive is the logical subject it is never preceded by a preposition: es necesario decirlo, it is necessary that I speak; importa arreglarlo, it is important to arrange it. See 413. 422.

13. The infinitive is preceded by a when it depends upon one of the following verbs: aprender, to learn, ensefiar, to teach, empezar (comenzar, principiar), to begin, and verbs of motion: aprendemos a hablar, we learn to speak; empezO a leer, he began to read; va a verme, he is coming to see me; vino a hablarnos, he came to speak to us. In the case of verbs of motion para may be used as connective, if it is desired to stress the purpose of the motion (see 410): fui a la ciudad para comprarme un traje, I went to the city to buy me a suit. 423.

14. Deber is regular in all its forms. But the English verbs, ought, must and should, the nearest equivalents of deber, are defective, lacking all tenses but the present. Hence the time idea that is conveyed by a given tense of deber often must be expressed in English by a perfect infinitive dependent upon ought, must or should. See examples in 425-427. 424.

15. Deber + infinitive denotes compulsion or necessity: debo ir alla, I ought to go there. Stronger than this would be tengo que ir