赶上
gǎn shàng · HSK 6
to catch up with
🏃 赶 (chase) + 上 (up/onto) = chase up onto = catch up with
赶 means to chase or rush; 上 means up or onto. Together they form 'chase onto' — you rush forward and land on the thing ahead, i.e. catch up with or overtake it. Also used for chancing upon something by timing.
赶 — walk radical 走 + 旱 (gan, phonetic)
赶 combines 走 'to walk/run' as the meaning component with 旱 as the phonetic clue for the sound gǎn. The walking radical points to its core meanings: to hurry, to chase, or to drive (animals) along. The simplified form replaced the older 趕, which used 倝 as phonetic.
上 — horizontal line above a baseline
上 is an indicative character (指事): a short stroke placed above a longer reference line shows the concept of 'above' or 'up'. The earliest oracle-bone forms used two horizontal lines for this; the modern shape added a vertical stroke for clarity. The core meaning of 'upper, above, to ascend' has stayed stable for millennia.