通
tōng · HSK 2
to connect
通 = walk radical 辶 + 甬 (yǒng) phonetic; 'to pass through'
As a measure word for events (calls, scoldings, conversations), 通 counts one complete go-through from start to finish. The core sense 'pass through / get through' extends to one full round of an action.
通 — 辵 (辶) walk + 甬 yǒng (phonetic)
通 is a semantic-phonetic compound. The 辶 (chuò) component means 'walk' or 'movement', giving the meaning of going through or passing. 甬 (yǒng), originally depicting a hanging bell or a path, supplies the sound. Together they convey 'to pass through, communicate, connect'.