German has two forms of the subjunctive: the general (der Konjunktiv II) and the special subjunctive (der Konjunktiv I). 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, whereas the special subjunctive is used to indicate indirectly reported speech (Note: the special subjunctive is not a grammatical structure found in English).
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 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.
The ‘du’ and ‘ihr’ forms can be formed with or without the ‘e’ in parentheses, depending on speaker preference.
‘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. Below is a chart of the modal verbs in Konjunktiv II, which only differ from their Imperfect forms insofar as umlauts present in infinitive forms are added back to the stem vowels.
For strong verbs, however, their imperfect forms differ enough to be easily identified (e.g. gehen → ich ging (imperfect) → ich ginge (subjunctive)). The form essentially is add an umlaut to stem vowel where possible + ‘e’ to end + ending when needed. Several strong verbs are as frequently used in their true subjunctive forms as with ‘würden,’ including: geben, finden, gehen, wissen, kommen, halten, lassen, tun, and heißen. These are listed in the chart below: