daddy

Compared meaning: father, as an informal or affectionate name (noun).

比较义项：爸爸，对父亲的称呼（名词）。

• dad

  The plain, everyday word for father, used by speakers of any age in ordinary conversation; neutral in tone, neither childish nor old-fashioned.

  最普通、最常用的“爸爸”一词，各年龄段的人在日常对话中都会使用；语气中性，既不显得幼稚，也不显得过时。

  My dad still calls me every Sunday to check how work is going.

  我爸爸每个星期天还是会打电话问我工作怎么样。

• daddy 本词

  A warm, childish form typically used by young children or when addressing a father affectionately; sounds odd or overly babyish from a grown adult in formal contexts.

  一种亲昵、带稚气的说法，通常是小孩子使用，或用来亲切地称呼父亲；如果成年人在正式场合这样说，会显得幼稚或不自然。

  The toddler cried out "Daddy!" the moment he walked through the door.

  那个学步的孩子一看到他走进门就喊“爸爸！”。

• papa

  An old-fashioned or storybook word for father, less common in everyday modern speech, often evoking an earlier generation or a nostalgic, quaint tone.

  一种老式或带有故事书色彩的“爸爸”说法，在现代日常口语中较少使用，常带有怀旧、上一辈的意味。

  In the old photograph, Grandpa is a boy sitting on his papa's knee.

  在那张旧照片里，爷爷还是个坐在他爸爸膝上的男孩。

All three are informal words for father. Dad is plain and everyday, neutral, used by speakers of any age. Daddy is warm and childish, typically used by young children; sounds odd from an adult. Papa is old-fashioned and less common today, evoking an earlier generation.

这三个词都是对“父亲”的口语称呼，但语气和使用人群不同：dad最中性、最常用；daddy多带稚气或亲昵语气，常见于儿童或撒娇场合；papa则显得老式、怀旧，常见于故事或长辈的回忆语境。