Future Tense: Consonants

Guttural

:
γ or κ or χ  ?
These letters cannot be followed by σ. And therefore ξ  is called for.

   today, normally, right now       tomorrow, in the future  
    λέγω      λέξω 
 διώκεις   διώξεις 
 παρέχει   παρέξει 
 φυλάττομεν   φυλάξομεν 
 ἄγετε   ἄξετε 
 ἀνοίγουσιν   ἀνοίξουσιν 
 δέχομαι   δέξομαι 
 εὔχῃ   εὔξῃ 
 ἕλκεται (drags itself)  ἕλξεται 
 
 
Oops, what is that  φυλάξομεν doing here?
As strange as it may seem, the original stem of
φυλάττω is φυλακ , as shown quite clearly by
ὁ φύλαξ, τοῦ φύλακος the guard (lesson six)

Most verbs in tt, often spelt ss even, originating from g or k stemmed forms follow the same pattern:

τάττω or τάσσω I place (in order) τάξω 
ἡ τάξις, τῆς τάξεως
the rank, order (in orderly order) not command.
 
πράττω or πράσσω I do πράξw
τὸ πράγμα, τοῦ πράγματος
act, deed, event, thing
ἡ πράξις, τῆς πράξεως activity, action, deed; business
πρακτικός, ή, όν practical.
 (praxis, a pragmatic person, practical)