Simple forms

There are four finite forms that can be classified along two categories tense and mood, the tense features being present and past, the mood features being indicative and subjunctive.

Using 3rd person singular, the forms for strong and weak verbs look like this:

| (strong)    | present | past   |
|-------------|---------|--------|
| indicative  | trägt   | trug   |
| subjunctive | trage   | trüge  |

|  (weak)     | present | past   |
|-------------|---------|--------|
| indicative  | macht   | machte |
| subjunctive | mache   | machte |

Past as a morphological feature is not the same as past tense. Most importantly, the past subjunctive (hätte, wäre, trüge …) does not refer to the past and the contrast between the two subjunctive forms is not of a temporal nature.

Therefore, a different terminology is often used. The subjunctive forms are usually referred to as Konjunktiv I (present subjunctive) and Konjunktiv II (past subjunctive). The indicative forms are called Präsens (present indicative) and Präteritum (past indicative).

It can be seen at this point that the phrase Konjunktiv 1 Vergangenheit im Präteritum contains a contradiction: Konjunktiv 1 and Präteritum are incompatible. Konjunktiv 1 and Vergangenheit, however, are not; see below.

The periphrastic past (perfect)

The periphrastically formed past tense is called the perfect. It is formed with an auxiliary verb haben or sein and a past participle. Since the auxiliary can take any of the four finite forms listed above, the perfect is actually a family of forms, depending on the form the auxiliary takes:

1. present indicative: er hat gearbeitet
2. past indicative: er hatte gearbeitet
3. present subjunctive (Konjunktiv I): er habe gearbeitet
4. past subjunctive (Konjunktiv II): er hätte gearbeitet

The Institut for Deutsche Sprache calls these tenses: 1. Indikativ Präsensperfekt, 2. Indikativ Präteritumperfekt, 3. Konjunktiv Präsensperfekt and 4. Konjunktiv Präteritumperfekt.

Konjunktiv Präsensperfekt combines Konjunktiv 1 (habe) and past tense.

Contexts where a perfect substitutes for a past indicative

The two past tenses – the past indicative (Präteritum) and the periphrastic perfect in all forms – both refer to the past. But the perfect, being a family of tenses, can express distinctions that the simple past cannot. Therefore, in certain cases, a shift from simple past to perfect occurs.

For instance, when a combination of past tense and Konjunktiv II is required, Konjunktiv Präteritumperfekt is used:

Er arbeitete nicht viel.

→ Er sieht nicht so aus, als hätte er viel gearbeitet.

When a combination of past tense and Konjunktiv I is required, Konjunktiv Präsensperfekt is used:

Er arbeitete nicht viel.

→ Ihm wurde vorgeworfen, er habe nicht viel gearbeitet.