As with the future tense, the forms of the conditional tense in Spanish hold few surprises. The endings are all regular, and there are only a few verbs that have irregular stems in the conditional. The endings (-ía, -ías, -ía, -íamos, -íaias, -ían) are added to the infinitive form of the verb or, in the case of the few irregular verbs, to the future stem.
Examples:
While most conditional tense occurrences are regular, there are a few irregular conditional and future stems, and they should be committed to memory. Notice how regular most of them are in their irregularity. They are:
Primary use of the conditional
tense
Conditional vs. imperfect tense
Contrary-to-fact clause
The conditional of conjecture or
probability
In its most basic sense, the conditional tense is a cousin to the future tense, not only in its forms but also in its meaning. Instead of translating the English will, however, it translates the words would or sometimes should. For example:
If a speaker says "would" in English to mean "used to," the
conditional tense is not used. Instead, the imperfect indicative is
used. For instance, When I was ten years old I would (used to)
play after school, They would (used to) go to Europe on
vacation.
The conditional and conditional perfect are used
in conjunction the imperfect
subjunctive and the pluperfect subjunctive to express
conditionality with respect to the main clause.
The conditional and conditional perfect tenses are frequently
used to express conjecture or probability in the past or
past perfect.
Conditional
perfect
"If" clauses
Imperfect indicative
Imperfect subjunctive
Future tense
Future perfect tense
Verbs