In Icelandic, the question words hver (who) and hvað (what) decline, changing their endings to match their grammatical role in the sentence.
Declining "Who"
When asking generally about a person ("who"), hver takes masculine endings. Notice how the verb or preposition determines the case:
| Case | "Who" |
|---|---|
| Nominative | hver |
| Accusative | hvern |
| Dative | hverjum |
| Genitive | hvers (whose) |
Use the accusative hvern when the person is the direct object of a verb like skilja (to understand):
| Whom does the psychologist want to understand now? | Hvern vill sálfræðingurinn skilja núna? |
Use the dative hverjum with verbs that require dative objects, such as hjálpa (to help):
| Whom does the psychologist want to help today? | Hverjum vill sálfræðingurinn hjálpa í dag? |
The genitive hvers translates directly to "whose":
| Whose depression is this? | Hvers þunglyndi er þetta? |
Declining "What"
The word hvað (what) shares the same genitive form as hver, but its accusative and dative differ:
| Case | "What" |
|---|---|
| Nominative | hvað |
| Accusative | hvað |
| Dative | hverju |
| Genitive | hvers |
Since the nominative and accusative are identical, you use hvað for subjects, direct objects, and after prepositions that take the accusative, like um (about):
| What does the mind talk about in the dream? | Um hvað talar hugurinn í draumnum? |
But when a verb like stjórna (to control) or a preposition like frá (from) requires the dative case, hvað becomes hverju:
| From what comes the trauma that you remember? | Frá hverju kemur áfallið sem þú manst? |
| What does the subconscious control? | Hverju stjórnar undirmeðvitundin? |
Indirect Questions and "Why"
These declined question words aren't just for direct questions. You will also use them in the middle of a sentence to form indirect questions about things you know, wonder, or cannot explain:
| I do not know whom the mind fears. | Ég veit ekki hvern hugurinn hræðist. |
Finally, the genitive hvers is part of the fixed phrase hvers vegna (why), which literally means "because of what":
| Why do you not remember the childhood? | Hvers vegna manst þú ekki barndóminn? |