A. Adverb.
'Achar (אַחַר, Strong's #310), “behind; after(wards).” A cognate of this word occurs in Ugaritic. 'Achar appears about 713 times in biblical Hebrew and in all periods. One adverbial use of 'achar has a local-spatial emphasis that means “behind”: “The singers went before, the players on instruments followed after …” (Ps. 68:25). Another adverbial usage has a temporal emphasis that can mean “afterwards”: “And I will fetch a morsel of bread, and comfort ye your hearts; after that ye shall pass on …” (Gen. 18:5).
B. Preposition.
'achar (אַחַר, Strong's #310), “behind; after.” 'Achar as a preposition can have a local-spatial significance, such as “behind”: “And the man said, They are departed hence; for I heard them say, Let us go to Dothan” (Gen. 37:17). As such, it can mean “follow after”: “And also the king that reigneth over you [will] continue following the Lord your God” (1 Sam. 12:14). 'Achar can signify “after” with a temporal emphasis: “And Noah lived after the flood three hundred and fifty years” (Gen. 9:28, the first biblical occurrence of the word). This same emphasis may occur when 'achar appears in the plural (cf. Gen. 19:6—localspatial; Gen. 17:8—temporal).
C. Conjunction.
'Achar (אַחַר, Strong's #310), “after.” 'Achar may be a conjunction, “after,” with a temporal emphasis: “And the days of Adam after he had begotten Seth were eight hundred years …” (Gen. 5:4).