Indo-European Grammar
Mood
Carol Justus and Jonathan Slocum
[IN PROGRESS]
Many problems still remain in the study of Indo-European morphology, particularly when one asks questions about the mapping of universal and typological structures to the changing ways that Indo-European morphological and syntactic forms encode functional categories.
In language generally, the grammatical category mood distinguishes functional pragmatic categories related to speaker attitude or intent. Traditional Indo-European inflectional mood categories include the indicative, imperative, subjunctive, and optative moods.
The table below relates Proto-Indo-European mood forms to their inflectional categories and the grammatical functions they perform.
| Mood Form | Inflectional Category | Grammatical Functions | ||
|---|---|---|---|---|
| no suffix + Person/Number Endings | indicative | statement of fact | ||
| no suffix + no ending or PIE *-u | imperative | command; request | ||
| PIE *-e-, dialectal variants | subjunctive | nonfactual, contrary to fact; request | ||
| PIE *-ye/-i- with dialectal variants | optative | wish, desire; request | ||
| Particles | [noninflectional] | mood variants | ||
| Modal Verbs | [noninflectional] | modalities |
Indicative mood forms give information that the speaker views as true (factual), while with imperatives speakers tell hearers what they want to have accomplished (commands). In languages that have both inflectional optatives and subjunctives, optatives express a wish ('Long live the king!'), while statements that the speaker views as non-factual or dependent on some condition are marked by the subjunctive mood ('If I were you...' as opposed to indicative 'I was you in the play about your life'). In many languages a range of information that the speaker does not intend to state as a fact or intend as an action to be carried out may be marked as subjunctive or optative. Individual language uses are often complex. In addition, Indo-Iranian has a formal "injunctive" mood, an inflectional form characterized by a lack of formal inflectional markers.
As the Indo-European languages differentiated and changed over time, a range of forms came to express functional categories of mood and modality. Not all older languages inflected for all moods, and some languages with inflectional suffixes added additional suffixes such as a DESIDERATIVE (Sanskrit). Other languages use particles instead of, or in addition to, inflectional endings to express speaker attitudes and intents, while Modern English has developed an entire class of modal verbs (e.g., 'may, could, would') for nuances of nonfactual information.
The history of English modal verbs goes back to the older Germanic class of preterit-present verbs, which in turn reflect a variant set of old verb class endings. English 'could' is the old past tense of 'can' related to older Gothic preterit-present kunnan (kann) 'know' with cognates of 'know' in many other older Indo-European languages that did not have this preterit-present class.