Abarim Publications' online Biblical Greek Dictionary
The particle ει (ei) is a conditional conjunction and means if. It's pretty much on a par with our English word "if", and offers no major surprises. It is employed to introduce a situation or statement that is entirely hypothetical, typically without saying anything about the validity of the statement.
Our particle occurs 504 times in the New Testament, see full concordance, and also serves as element of a few compounds:
- Together with the curious particle αν (an), which expresses supposition or wish: the conjunction εαν (ean), meaning something like "if it would". This word occurs 343 times; see full concordance. From this word in turn comes:
- Together with the conjunction τε (te), meaning "and": the conjunction ειτε (eite), meaning "and if" or "whether", which occurs 65 times; see full concordance.
- Together with the nominative single form of the relative pronoun, ος (hos), meaning "that/who/which": the adverb ωσπερει (hosperei), meaning wholly as if, just as it were. This useful concoction occurs in 1 Corinthians 15:8 only.