Conditional clauses are dependent clauses that are introduced by the subordinating conjunction wenn. They express that an action will only take place under certain conditions. Conditional clauses can describe realistic situations as well as hypothetical ones.
German has two forms of the subjunctive: the general and the special subjunctive. The general is the one native English speakers think of when referring to the subjunctive (e.g. could, would, should). This grammatical mood indicates hypothetical or unreal/imaginary situations, including wishes and desires.
Example: I could run a marathon if I were in shape.
The modal verb ‘could’ is the subjunctive form of ‘can.’ In this case, it is not a question of whether the speaker is physically able to run a marathon in his/her present condition or level of fitness; rather, it is speculation based on a hypothetical level of physical fitness. Notice that the word ‘were’ is also in bold in the example. This is the subjunctive of the verb ‘to be,’ and looks similar to the German equivalent. Consider the translation of the above example into German:
Ich könnte einen Marathon laufen, wenn ich fit wäre.
Typically, we find hypotheticals posited as conditionals (e.g. If X, then Y). Similarly, in German, Konjunktiv II is often expressed using the subordinating conjunction ‘wenn’ (if):
Wenn ich reich wäre, könnte ich mir einen Ferrari leisten. If I were rich, I could afford a Ferrari.
In the present tense subjunctive, there are three forms to learn: ‘hätten,’ ‘wären,’ and ‘würden’+ Infinitiv. Below are the conjugations of these verbs.
‘Wären’ (were) and ‘hätten’ (had) can stand alone in the present tense subjunctive. The modal verbs and ‘würden,’ however, require an infinitive form of the main verb at the end of the sentence or clause. For example:
Ich könnte Fußball spielen, wenn ich Zeit hätte. AND Ich würde Fußball spielen, aber ich bin nicht fit.
The ‘würden’ + Infinitiv form is used for all regular verbs and often for most strong verbs, too, despite the latter having their own forms. The reason for this is that the subjunctive and imperfect forms of regular verbs are identical (e.g. spielte / spielte), which makes it difficult to recognize.