The base sense is simple: to lift and carry. From there Hebrew spreads it in every direction. You carry a load, you carry yourself in a speech, you carry someone in marriage (לָשֵׂאת אִשָּׁה, "to take a wife"), and the one lifted above the people is the נָשִׂיא, the president. The same lift gives the topic you raise, the financial yield you bring in, and even the beacon raised on a hill. 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.
Watch the marriage thread climb through the voices: pa'al לָשֵׂאת = to marry (take a spouse), nif'al לְהִנָּשֵׂא = to be married, hif'il לְהַשִּׂיא = to marry someone off (cause the marriage). One root, three perspectives on the same event. The pu'al / huf'al slots are not lexicalized; the hitpa'el survives only inside an adjective (see below).
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.