到
dào · HSK 1
up until
🎯 到 = 刂 (knife/arrive radical) + 至 (reach); means to arrive at or up until
至 alone means 'to reach'; adding the 刂 component gives 到, the verb 'arrive at'. As a preposition it marks the endpoint: 从一到十 = from one up until ten.
到 — 刂 knife + 至 (phonetic, 'arrive')
到 is a semantic-phonetic compound. 至 ('to arrive') gives both meaning and sound, while 刂 (knife) was added later, likely as a phonetic reinforcer or to distinguish the written form. The core sense 'to arrive, reach' comes directly from 至, and 到 has carried that meaning since early script forms.