The subjunctive is the verbal mood of possibility, doubt, hypothetical or ideal situations, or unreal actions. It can be used either in independent clauses or subordinate clauses. We will learn about one independent uses (deliberative) and one dependent use (temporal clauses) this semester.
The subjunctive exists only in four tenses: present, imperfect, perfect, and pluperfect. The future and future perfect do not have subjunctive forms because they express actual situations or real facts.
To form the subjunctive in the present tense, we begin as usual by finding the present stem (by going to the 2nd principal part and chopping off the final -re). Then, depending on the conjugation to which the verb belongs, the vowel at the end of the present stem will undergo a shift:
This pattern can be memorized using the mnemonic: shE wEArs A dIAmond tIAra.
Then, we attach the appropriate personal endings to reflect person, number, and voice: -m, -s, -t, -mus, -tis, -nt for the active; -r, -ris, -tur, -mur, -minī, -ntur for the passive.
Take a look at the following transformations from indicative to subjunctive:
To form the imperfect subjunctive, we will take the entire 2nd principal part and then simply add our active or passive personal endings directly onto it. The final -e lengthens to ē except before -m, -t, -nt, -r, and -ntur.
Take a look at the following examples of the imperfect subjunctive in the 3rd singular active and passive (respectively):
To form the perfect subjunctive, we will use the perfect stem, which can be found by going to the 3rd principal part and chopping off the final -ī. Then, we will attach the following endings:
These endings are composed of the syllable cluster -erī- with the active personal endings.
Take a look at the following transformations from perfect indicative to perfect subjunctive:
To form the pluperfect subjunctive, we will use the perfect stem, which can be found by going to the 3rd principal part and chopping off the final -ī. Then, we will attach the following endings:
These endings are composed of the syllable cluster -issē- with the active personal endings.
Take a look at the following transformations from pluperfect indicative to pluperfect subjunctive:
The perfect and pluperfect passive subjunctive, like their indicative counterparts, are compound tenses. We will observe the same rules for the formation of the perfect and pluperfect passive (i.e., use a form of the 4th principal part that matches the subject in gender, case, and number plus the present tense of sum, esse for perfect and the imperfect tense of sum, esse for pluperfect), but rather than using the indicative forms of sum, esse, we will use the subjunctive forms.
Take a look at the following transformations from the perfect passive indicative to the perfect passive subjunctive:
Now, take a look at the following transformations from the pluperfect passive indicative to the pluperfect passive subjunctive: