To mark something is the seed of this root, and it grows in two directions at once. Outward, into the world: you note, register, list, prescribe, sketch. Inward, into the mind: something leaves an impression on you, and an impressive thing impresses. The same act of leaving a mark covers a clerk's register and a painting that takes your breath away. Every form 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.
Three binyanim split the labour neatly: the plain pa'al marks something down, the nif'al is its passive-reflexive (to get registered, to sign yourself up), and the causative hif'il turns the mark inward, to make an impression on someone. The passive partners pu'al and huf'al are not lexicalized here.
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.