The infinitive form of the verb is: emagon

emagon [e'magon]

perfect: ēdan

v. C-fin. (irreg.) [High Valyrian Verb Tables: Consonant-final, irregular] to have. 3s. pres. act. ind. ēza, 3pl. ēzi, imperfect emilen, emiles, etc.)

From Dothraki Wiki: https://wiki.dothraki.org/High_Valyrian_Vocabulary

Note: this verb is irregular indeed!

Present active (Indicative): eman (1s), emā (2s), ēza (3s), emi (1pl), emāt (2pl), ēzi (3pl)

Emagon, and verbs derived from it, are essentially regular consonant stems, with the sole exception that in the third person forms of the present active indicative, the nasal-dropping forms are mandatory.

https://wiki.dothraki.org/High_Valyrian_Verb_Tables#emagon