3.6.3 Irregular subjunctive conjugations
The 6 true irregulars are:
DISHES
DAR
IR

SER
HABER
ESTAR
SABER
These are the 6 verbs that don’t end in an -o in the present yo form. So if you were going along and applying your “drop the -o” rule to all the verbs you know how to conjugate, you’d run into a problem with these 6. Here are the forms:
| Dar | Ir | Ser | Haber | Estar | Saber | |
| Present indicative yo form | doy | voy | soy | he | estoy | sé |
| Subjunctive | ||||||
| yo | dé | vaya | sea | haya | esté | sepa |
| tú/vos | des | vayas | seas | hayas | estés | sepas |
| él/usted | dé | vaya | sea | haya | esté | sepa |
| nosotros | demos | vayamos | seamos | hayamos | estemos | sepamos |
| vosotros | deis | vayáis | seáis | hayáis | estéis | sepáis |
| ellos/ustedes | den | vayan | sean | hayan | estén | sepan |