# εἰ/ei
This word may tell something about the speaker's attitude toward what he is talking about. Or it may tell something about how one group of words in the sentence is related to another group of words. It is a particle.

* This word is used when questioning something or talking about something that the writer is not sure about. When this word is used in this way, it means if or whether. 

Sometimes this word is used to organize what someone wrote. It relates two ideas or groups of words to one another in some way. It is a conjunction.

* This word is used when starting to write something that might be true. When this word is used in this way, it means if.
    * Sometimes the writer thinks what they are writing is true.
    * Sometimes the writer thinks what they are writing is not true. 

Sometimes this word is used to describe an action or situation or to relate two ideas. It is an adverb.

* It means if. It describes an action that might or could happen. 

Sometimes this word is used with other words.

* When it is used with μή (G3361), they mean if not, unless, or except. 
* When it is used with μήν (G3375), they mean surely. 
* When it is used with εἴτε or τε (G1535, G5037), they mean whether.
