εἰμί to be versus εἶμι I'll go

 

Present Indicative + Future Indicative

Compare:

Tenseto beto go
Present
Indicative 		I am 
you are 
he/she/it is 
we are 
you are 
they are 		 εἰμί
εἶ
ἐστίν
ἐσμέν
ἐστέ
εἰσίν 		ἔρχομαι
ἔρχει/ἔρχῃ
ἔρχεται
ἐρχόμεθα
ἔρχεστε
ἔρχονται		 I go 
you go 
he/she/it goes 
we go 
you go 
they go 
Future
Indicative 		I shall be 
you will be 
he/she/it will be 
we shall be 
you'll be 
they'll 		 ἔσομαι
ἔσῃ/ἔσει
ἔσται
ἐσόμεθα  
ἔσεσθε
ἔσονται		 εἶμι
εἶ
εἶσι
ἴμεν
ἴτε
ἴασιν		 I'll go 
you'll go 
he/she/it'll go 
we'll go 
you'll go 
they'll go 
 
  1. εἰμί (to be) in the present indicative is an  enclitic  and as such can only be accented on the last syllable (except for ἔστιν after οὐκ, ἀλλ' (+ a few others) and in the sense of "there is")
    And εἶ "you are" is the famous exception to any rule.
    εἶμι (I'll go) is a full verb in the future indicative and as such the accent will always be as near to the front of the verb as possible. Only 2 syllables means "on the first syllable, always".
     

  2. The future tense of "to come" ἔρχομαι is εἶμι that conjugates like a regular -μι  verb in the present indicative , except for "you will go" missing a sigma at the end.
    -μι verbs have a long stem vowel in the singular, in this case εἶ
    -μι verbs have a short stem in the plural, in this case ἰ
    and add the -mi verb endings straight to that stem:

      long stem     μι  
      ς
      σι
      short stem     μεν  
      τε
      ασιν  
     
    Unfortunately the you-singular form wants to play odd man out and lost its ς.
 

Practice Makes Perfect

Fill in the following table
Present tense of  πάρειμι 'to be present' versus
future tense of  πάρειμι 'I shall go away'
 
 Note 
In compounds εἰμί 'to be' is not enclitic
Compounds of both εἰμί and εἶμι are normal verbs and therefore the accent is recessive, i.e. moves as far towards the front of the verb as possible.
 
  is present      Who?       will go past  
  πάρειμι    I   πάρειμι  
________________  you (sg) ________________ 
   he/she/it  
   we  
   you (pl)  
   they  
 

Translate the following

1. πότε ἄπει;
- οὐκ οἶδα ὅποτε ἄπειμι.
2. ἄπεισιν;
- οὔπω, ἀπίασιν αὔριον.
3. πάρεστιν;
- οὐχί, ἄπεστιν. εἶσιν ὕστερον.
4. ἐσμὲν ἐν τοῖς ἀγροῖς. ἴμεν δὲ Ἀθήναζε ὡς θεασόμενοι τοὺς χορούς.