There are several ways conditional verbs are used including:

1. Where one would, could, should, ought to do something (e.g., Je voudrais de l’eau/I would like some water and Je devrais trouver un travail/ I ought to get a job).  Note that ought to is followed by an infinitive verb.  The same can be used with could or would be able when using pouvoir.
2. An action that one would or could do if something else were possible (e.g., Je rentrerais chez moi si j’avais une voiture/I would go home if I had a car).  Note in this example the conditional and the imparfait form of the second verb.  The phrase can also be flipped around such as If I had a car, I would go home.

The accompanying practice question exercise will cover the conditional of the most popular verbs.  We recommend that you use a verb list with the conditional forms (or the book 501 French Verbs available for purchase online as noted elsewhere on our site) and understand how to conjugate conditional verbs before starting this exercise.  In short, take the full verb and add the imparfait (one of the past tenses) endings to it (-ais, -ais, -ait, -ions, -iez, -aient).  For example, Douter (to doubt) would in the imparfait form get the -er dropped (e.g, je doutais) and add those aforementioned imparfait endings.  The conditional doesn’t drop the er and just adds those imparfait endings to the verb non conjugated (e.g., je douterais).  In learning and practicing imparfait, you will become better at conditionel.

There are some exceptions to this where verbs change accents, add an extra letter, change a -yer ending to an i so pay attention when reading the questions for these changes.  The best way to learn them comes from observation, reading, and practice, but fortunately these exceptions (avoir and être being exempted) do not appear frequently in testing and if they do, are found on the last part of the test.

Note that there are a few exceptions such as avoir and être that must be memorized.

Unless required, an explanation will not be given as the objective is to just select the correct form of the verb in the conditional.  It will be mixed up with other forms of the verb.  When a deliberate error is placed in the options (e.g., a spelling error) or there is a particular trick, these will most often be noted in the explanation.