Learn Hardcore Japanese: asagohan wo tabezuni gakkou ni ikimasita. - I went to school without eating breakfast.

食べずに is the negative conjunctive form of 食べる. It’s formed by taking the plain negative 食べない, dropping ない, and adding ずに. Together it means without eating.

How does ずに differ from ないで when expressing “without doing” something?

Both constructions mean “without doing”, but ずに is somewhat more formal or literary, while ないで is more common in everyday speech. You could say 朝ご飯を食べないで学校に行きました with identical meaning in casual conversation.

Why is there a に after 学校?

The particle に marks a destination or goal of movement. In 学校に行きました, に tells you “to school”—that is where the subject went.

Could the object marker を be omitted in 朝ご飯を食べずに?

In very casual speech you might drop を and say 朝ご飯食べずに, but it’s more standard and clearer to include を to mark 朝ご飯 as the direct object.

What’s the difference between 朝ご飯 and 朝食?

Both mean breakfast, but 朝ご飯 is more colloquial and common in conversation, while 朝食 is a bit more formal or used in writing.

Why is 行きました in the polite past form rather than the plain past?

行きました is the polite past of 行く. If you want a more casual tone, you could use the plain past 行った, as in 朝ご飯を食べずに学校に行った.