One forbidden act drives this root: stealing, taking by stealth. The pa'al לִגְנֹב is one of the Ten Commandments. But the deeper idea is doing something unseen, and the binyanim spread it: to be stolen (nif'al), to smuggle or slip something in (hif'il), and to sneak in yourself (hitpa'el). Modern slang even turned the participle גָּנוּב (stolen) into "awesome", what's stolen is desirable. The root covers four binyanim plus a tight noun family. Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
Four binyanim, each a different angle on stealth. Pa'al steals (active); nif'al is stolen (passive); hif'il is the causative "make something slip in unseen", smuggle, or slyly insinuate a remark; hitpa'el turns it reflexive, you yourself sneak in. The passive pu'al and huf'al are not lexicalized; nif'al carries "to be stolen".
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.