χαίρετε!
I am beginning Unit 23 which introduces me to μι verbs.
It looks like verbs such as ζεύγνυμι and δείκνυμι keep the νυ just before the endings in the present stem in the active and passive present and imperfect, but it looks from the principal parts that the νυ gets tossed with the future and the rest. Is that correct?
You’re more or less right, but you should think in terms of stems. You shouldn’t think of it as “ditching” the -νυ-. -νυ- is a suffix that’s added to the root to form the present stem of these verbs and is conjugated athematically in the indicative (present and imperfect), imperative, participle and infinitive (but not subjunctive or optative).
Other stems – future, aorist, perfect and aorist passive – are formed from the root without the suffix and conjugated like the other verbs.
I just noticed that the future of ἵστημι is στήσω and the future of ἵημι is ἥσω. Does the iota fall off because it was part of a reduplication without a consonant?
Page 193, section 8, Historical Notes
That’s very perceptive, Lukas. The aspirated ι in the present stem of both of these verbs is indeed due to reduplication. At a very early period, long before the earliest written Greek texts, σ, when it occurred at the beginning of a word or between two vowels, became very weak in pronunciation. Eventually, at the beginning of a word, σ came to be nothing more than an aspiration of the following vowel, and between two vowels it ceased to be pronounced altogether. (Of course, there are many Greek words beginning with σ-; the weakening of initial σ- must have ceased to operate at some point in the history of Greek.)
Thus, the original forms of these present tenses were *σιστημι and *σισημι. The σ in ἵστημι and other forms of this verb without reduplication continued to be pronounced – it wasn’t sandwiched between two vowels – but the initial σ- that had previously been present in forms of ἵημι without reduplication, from the root *ση-, was weakened into just an aspiration of the vowel η.
Note that future tenses of both athematic verbs (e.g., στήσω and ἥσω) and thematic verbs (e.g., λυσω, ποιησω) with stems ending in a vowel haven’t undergone the weakening and disappearance of -σ- between two vowels. This is probably because the future tense, which is a relatively recent development in Greek, began to take shape after the process of weakening of intervocalic -σ- ceased to be operative, or because the intervocalic -σ- marking the future tense resisted the process, since in many words the future would have been indistinguishable from the present.