难以忘怀 (nán yǐ wàng huái) — unforgettable; hard to forget; never to be forgotten

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 難; 难 is its simplified writing.

The traditional 難 pairs 隹, a bird, with 暵 for sound, and meant a type of bird. It was later borrowed for other meanings; the modern 难 is a shorthand.

A drawing of the thing itself, worn down over three thousand years into a few strokes.

The shape came from a drawing of a person carrying something; in 以, part of that person is still visible on the right.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

忘 combines 亡, which gives the sound, with 心 (“heart”), showing the sense is about the heart or mind.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 懷; 怀 is its simplified writing.

The traditional form 懷 uses 心 (heart) to show longing and 褱 for the sound; the simplified 怀 is a later shorthand.