Pitman's Commercial Spanish Grammar (2nd ed.)

Impersonal verbs are those which are only conjugated in the 3rd pers. sing, of all the tenses.[129]

Footnote 129: They are so called because they have no person or thing as their subject.

The principal Impersonal Verbs are --

Llover-llueve (to rain, it rains)
Granizar (to hail)
Helar-hiela (to freeze, it freezes)
Lloviznar (to drizzle)
Nevar-nieva (to snow, it snows)
Relampaguear (to lighten)
Tronar-truena (to thunder, it thunders)
Alborear (to dawn)
Amanecer (to dawn)
Anochecer (to grow dark)

The subject (generally understood) of Impersonal verbs is ello. Sometimes we find the words Dios or el día expressed as subjects, as --

Amanecerá Dios y veremos: Let us wait for the morning and then we shall see.

Amaneció el día: The day dawned.

Amanecer and anochecer may be used as personal verbs, as --

Amanecimos en Madrid y anochecimos en Guadalajara: We were in Madrid at daybreak and at nightfall in Guadalajara.

Tú anocheciste bueno y amaneciste malo: You passed the night well, but you had a bad morning.

Many ordinary verbs are used sometimes impersonally, as --

Bastar (to suffice).
Convenir (to suit).
Parecer (to appear).
Faltar[130] (to be wanting).
Hacer falta (to be wanted).
Suceder[131] (to happen).

Footnote 130: As a personal verb, it means also "to fail."

Footnote 131: As a personal verb, it means also "to succeed."

EXAMPLES --

Basta ganar la vida: It is enough to earn a living.

No conviene explotar esta mina: It does not pay to exploit this mine.

No parece justo que se aprovechen de este modo: It does not seem right that they should take advantage in this way.

Falta hacer algunos arreglos: Some arrangements are still wanting.

Sucedió que se declaró en quiebra: It happened that he filed his petition in bankruptcy.

In the sentences:

Me bastan diez libras: £10 are enough for me. Me parecen justas sus razones: His reasons seem to me to be right. Le sucedieron muchas desgracias: Many misfortunes happened to him.

the verb is personal, and this accounts for its being in the plural. In "me bastan diez libras," "diez libras" is the subject.

The verb is impersonal when referring to a whole statement, as --

(Ello) es necesario: It is necessary.

Of Haber and Hacer as impersonal verbs, we have treated in Lesson VIII and Lesson XVI.

We add here that Hacer is used impersonally before certain nouns to denote the state of the weather or of the temperature, as --

Hace calor, frío, lluvia, viento, sol, etc.: It is warm, cold, rainy, windy, sunny, etc.

Valer used impersonally = "to be better," as --

Más vale así: It is better so.

Expressions like "¿Qué se dirá?" or "¿qué dirán?" (What will people say?) may also be called impersonal uses of the verb.

Irregular Verbs (contd.).

                   Andar (to walk, to go).

 Past Def.,        Anduve,-iste,-uvo,-uvimos-uvisteis-uvieron.

                   Dar (to give).

 Pres. Indic.,     Doy,[132] das, da, damos, dais, dan.
 Pres. Subj.,      Dé, des, dé, demos, deis, den.
 Past Def.,        Dí, diste, dió, dimos, disteis, dieron.

Footnote 132: Only 6 verbs in Spanish do not end in o in the 1st pers. sing., pres. indic., viz., Doy (I give), Soy (I am), Estoy (I am), Voy (I see), He (I have), Sé (I know).