Abarim Publications' online Biblical Greek Dictionary
There are really three different prefixes that look like the same α- (a-). But these three a-'s are remnants of different words and mean different things:
- The most familiar α- (a-) is the negating α- (a-). It survives into modern English and is probably a leftover from ανευ (aneu), meaning without, or ατερ (ater), meaning apart from. When this α- (a-) is tied to a word that starts with a vowel, it comes with an added ν (n).
- The intensifying α- (a-) probably stems from αγαν (agan), meaning very much. An example of the use of this prefix is in the verb ατενιζω (atenizo), meaning to look intently, from the verb τεινω teino, meaning to stretch or strain.
- The collecting α- (a-) comes from αμα (hama), meaning together with. An example of the use of this prefix is in the noun αδελφος (adelphos), meaning brother, from the noun δελφυς (delphus), meaning womb.