Three consonants carry one idea: to know. The plain verb is bare knowing; push the same letters through the other moulds and knowing becomes making-known, informing, announcing, broadcasting. That single shift, from holding knowledge to passing it on, is what splits this family into two halves: the words for what you know (knowledge, opinion, science, information) and the words for letting others know (a notice, a message, an ad, the intelligence service). None are memorized separately; they are the same three letters seen from different angles. 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.
Pa'al is the seat of the meaning: just to know. Nif'al turns it passive (knowledge becomes known), while pi'el and hif'il both push toward causing knowledge, informing and announcing. The passive partners pu'al and huf'al exist in the system but are not lexicalized for this root, and hitpa'el is not in everyday use, so the family lives mainly in these four. That is normal: not every root fills all seven binyanim.
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.