Soler requires an infinitive as a complement, although it's possible for that infinitive to be implied rather than explicit.
RAE describes this verb as a "defective verb", because it does not have forms for all tenses and moods. The conjugation page for it lists the infinitive, the
gerundio, the present indicative, the present subjunctive, the imperfect indicative, and the imperfect subjunctive. The
DPD also states that it it rarely used in the present perfect; that article gives a regular past participle. It does not have forms for the preterite tense, future tense, conditional tense, or imperative mood.