Defective Verbs are those only certain parts of which are in use, the rest having never existed in the language or having died out of it.

The principal ones are:

Soler. "To be wont," "to be accustomed to." Used in the present indicative:

Suelo      Solemos
Sueles     Soleis
Suele      Suelen

in the imperfect indicative,

• Solía, solías, etc.

and in the present perfect:

He solido, has solido, etc., as:

• En su juventud solía trabajar con ahinco--ahora ya ha aflojado un poco.
  When he was young he used to work with fervour, now he begins to flag a little.

Yacer. "To lie"; generally on tombstones, as:

• Placer (to please). Generally used in "Plegue á Dios" (may it please God) and "Pluguiera (pluguiese) á Dios" (might it please God).

  It is still used also in the 3rd pers. of Pres. Indic., Imperf. Indic, and Past Def. (the Past Def. is "Plugo").

  Examples
  • Mucho me place.
    It pleases me much.
  • Plegue á Dios que no se declare la huelga.
    May it please God that a strike is not declared.

  Abolir (to abolish) is irregular like "mover" (viz., changes "o" into "ue" when stressed). Its irregular parts are however never used, and are substituted by giving a different turn to the sentence, as:

  • Digo que se debe abolir instead of se abuela:
    I say that it must be abolished.

  Atañer (to bear upon) is only used in the 3rd pers., as:

  • Lo que atañe al asunto.
    What bears on the subject.
  • Las noticias que atañen a nuestro proyecto.
    The news that bears on our scheme.

  Concerner (to concern) is only used in the pres. participle--concerniendo (concerning) and in the 3rd persons, as:
  concierne (it concerns), etc.

  Pronominal Verbs are verbs conjugated throughout with a double pronoun of the same person, as:
  Amarse,

  
  Yo me amo      nosotros nos amamos
  tú te amas     vosotros os amais
  el se ama      ellos se aman
  

  These are:

  1. Reflexive Verbs (when the action falls back on the subject. See Lesson: Transitive Verbs), as--Yo me amo: I love myself.

2. Intransitive Pronominal Verbs (see Lesson: Intransitive Verbs).

3. Intransitive Verbs made Pronominal from verbs ordinarily transitive
(see Lesson: Intransitive Verbs), as--

• Hacerse, Volverse.
  To become.
• La competencia se ha hecho imposible.
  Competition has become impossible.

4. The 3rd pers. pronominal forms the Passive Voice, same as the verb
ser, as:

• La sabiduría se alaba or es alabada.
  Wisdom is praised.

• La sabiduría se alaba por todos.
  Wisdom is praised by all. (Grammar of the Academy.)

Pronominal Verbs are used in Spanish very frequently in conjunction with the article to avoid the use of the possessive adjective before parts of the body, or articles of dress,[2] as:

• Me he quebrado la pierna.
  I broke my leg.
• Se ha dañado los ojos, or la vista.
  He has damaged his eyes or eyesight.