Future Tense: Consonants

I said "Insert an S". So what happens if the stem does not end in a dental, labial or guttural consonant?
It's all a question of sound: some work well, some don't work at all. For the Greeks, that is.
Let's now consider those that don't work so well:

Just as we don't like "watchs, brushs, axs" and insert an "e" between the stem and the plural marker s, the Greeks inserted an ε between the stem and the future marker σ:
μένω - μενέσω
αἴρω - αἰρέσω
But they didn't like that either, so they dropped the σ and then contracted the resultant form:
μένω - I'll stay: [μενέω] μενῶ
πληθύνω - I shall make full, multiply: πληθυνῶ (chapter 2b, Dikaiopolis invoking Demeter: ἵλαος|ἵλεως ἴσθι, ὦ Δήμητερ, καὶ πλήθυνε τὸ σπέρμα)
οἰκτίρω - I shall pity: οἰκτιρῶ (chapter 6a: ὁ Θησεὺς τοὺς ἑταίρους οἰκτίρει καὶ βούλεται βοηθεῖν αὐτοῖς)
αἴρω - [αἰρέω] αἰρῶ No, this didn't sound good either and therefore diphthongs ει and αι lost their iota and became single vowel ε or α.
I shall lift: ἀρῶ
θερμαίνω -I shall heat up: θερμανῶ (chapter 7b: τοὺς ἑταίρους κελεύει θερμαίνειν τὸ ῥόπαλον (τὸν μοχλὸν) ἐν τῷ πυρί.)
σπείρω - I shall scatter: σπερῶ
ἀποκτείνω - I shall kill: ἀποκτενῶ
ἐγείρω - I shall wake someone up: [ἐγερέω] ἐγερῶ
ἐγείρομαι - I'll wake up: [ἐγερέομαι] ἐγεροῦμαι
περαίνω - I shall finish: περανῶ (chapter 6b: οὔτω περαίνει τὸν μῦθον ἡ Μυρρίνη.)
ὑφαίνω - I shall weave: ὑφανῶ
βάλλω - I shall throw, pelt: βαλῶ (lost one lambda)
στέλλω - I shall send, furnish; take down (sails): στελῶ (Chapter 7b: Theseus' father says: στέλλε μὲν τὰ μέλανα ἱστία, αἶρε δὲ τὰ ἱστία λεῦκα.. But Theseus λήσεται [will forget] καὶ οὐ στελεῖ τὰ λεῦκα.)
ἀποκρίνομαι - I shall answer: [ἀποκρινέομαι] ἀποκρινοῦμαι
 
 
 
 
 
 
 
 
 

 
Most verbs ending in -ιζω don't change their ζ to σ, they drop it and replace it with an ε inserted before the normal endings, which in Attic Greek contract of course:
See future tables for κομίζειν, to take/bring.

κομίζω - I shall take: [κομιέω] κομιῶ (chapter 11a)
κομίζομαι - I shall acquire: [κομιέομαι] κομιοῦμαι
ὀργίζω - I shall anger someone else, make angry: ὀργιῶ
ὀργίζομαι - I shall get angry: ὀργιοῦμαι
καθίζω - I shall sit: [καθιέω] καθιῶ
οἰκίζω - I shall build [houses], colonize, settle: [οἰκιέω] οἰκιῶ
ἀγωνίζομαι - I shall struggle: ἀγωνιοῦμαι
ὤθίζω - I shall push: ὠθιῶ
ἐμποδίζω - I shall impede: ἐμποδιῶ
etc.