Breakdown of haha wa toosuto ni bataa de wa naku mayoneezu o nutte tabemasu.
Questions & Answers about haha wa toosuto ni bataa de wa naku mayoneezu o nutte tabemasu.
は marks 母 as the topic: As for my mother, ...
So 母は sounds like the speaker is introducing what their mother does. This is very natural in a general statement.
If you used が instead, it would put more focus on mother as the one who does the action, often with a nuance like my mother is the one who... That is not impossible, but は is the more natural choice here.
With the verb ぬる (to spread / apply), the thing you put something onto is often marked with に.
So:
- トーストに = onto the toast
- マヨネーズを = the mayonnaise as the thing being spread
This is a very common pattern:
- パンにジャムをぬる = spread jam on bread
- 壁にペンキをぬる = apply paint to a wall
So here, に does not mean a destination like to school. It marks the surface or target of the spreading.
