asagohan ni pan o taberu toki, watashi wa bataa yori jamu no hou o yoku tsukaimasu.

When I eat bread for breakfast, I use jam more often than butter.

Breakdown of asagohan ni pan o taberu toki, watashi wa bataa yori jamu no hou o yoku tsukaimasu.

• は: topic particle
• 私わたし: I
• を: direct object particle
• 食たべる: to eat

Questions & Answers about asagohan ni pan o taberu toki, watashi wa bataa yori jamu no hou o yoku tsukaimasu.

Why is に used after 朝ご飯?

Here, に marks the occasion or mealtime: for breakfast / at breakfast.

So 朝ご飯にパンを食べる means eat bread for breakfast.

This に is common with meals:

• 朝ご飯にパンを食べます = I eat bread for breakfast.
• 昼ご飯にうどんを食べます = I eat udon for lunch.

It is not the destination に here.

Why is it パンを食べるとき and not パンを食べますとき?

Because the part before とき is a clause modifying a noun, and Japanese uses the plain form before nouns.

• とき means time / when
• パンを食べるとき literally means the time when I eat bread

So:

• 食べるとき = when I eat
• not 食べますとき

This is the same pattern as:

• 日本へ行くとき = when I go to Japan
• 忙しいとき = when I’m busy

Why is it 食べるとき instead of 食べたとき?