Strong's Definition
from 3559 (compare 3651); firmly; figuratively, surely; also (advers.) but
KJV Usage: but, certainly, nevertheless, surely, truly, verily
STEPBible — Tyndale Abridged Hebrew Lexicon
אָכֵן (a.khen) — surely. 1) surely, truly, indeed 1a) truly, indeed (strong assertive force) 1b) but indeed, but in fact (emphasizing a contrast)
UBS Dictionary of Biblical Hebrew
intj
Affirmers
surely, certainly, truly = marker used to affirm the truth of the following statement
GEN 28:16 · EXO 2:14 · 1SA 15:32 · 1KI 11:2 · ISA 40:7 · JER 3:23 · JER 3:23
Affirmers | Contrastors
however, yet, but, but truly, the truth is, nevertheless = marker used to affirm the truth of the following statement, which is in contrast with what was assumed to be the truth earlier on
JOB 32:8 · PSA 31:23 · PSA 66:19 · PSA 82:7 · ISA 45:15 · ISA 49:4 · ISA 53:4 · JER 3:20 · JER 4:10 · JER 8:8 · ZEP 3:7
UBS Dictionary of Biblical Hebrew © United Bible Societies, licensed CC BY-SA 4.0.
Brown-Driver-Briggs Hebrew Lexicon
אָכֵן adv. with strong asseverative force: surely, truly
emphasizing a contrast, but indeed, but in fact
base