konya no karee no zairyou wa mou nabe no yoko ni oite aru.

A natural breakdown is:

• 今夜のカレーの材料 = the ingredients for tonight’s curry
• は = topic marker
• もう = already
• 鍋の横に = next to the pot
• 置いてある = have been placed / are set there

So the overall structure is:

• As for the ingredients for tonight’s curry, they have already been placed next to the pot.

Japanese often builds a sentence by introducing the topic first, then saying something about it.

Each の links nouns together, a bit like of or an apostrophe-s in English.

Here is the chain:

• 今夜のカレー = tonight’s curry
• 今夜のカレーの材料 = the ingredients of tonight’s curry

In more natural English, that becomes:

• the ingredients for tonight’s curry

So の does not always translate as of literally. It just connects nouns, and the exact English wording depends on what sounds natural.

は marks 材料 as the topic of the sentence.

The sentence is not mainly saying what exists; it is saying something about the ingredients. So:

• 今夜のカレーの材料は = as for the ingredients for tonight’s curry...

Then the rest of the sentence tells you their state/location:

• もう鍋の横に置いてある = they have already been placed next to the pot

If you used が instead, the nuance would shift. は feels more like introducing or contrasting a known topic.

もう here means already.

It shows that the action/state is complete earlier than expected, or at least before some reference point:

• もう置いてある = they’ve already been put there

So the sentence has a nuance like:

• The ingredients are already set out next to the pot.

It often implies preparation has been done in advance.

置いてある comes from:

• 置く = to place, to put
• 〜てある = something has been done and the result remains, usually intentionally

So 置いてある does not just mean to be sitting there in a neutral sense. It suggests:

• someone placed it there on purpose
• it is still there in that placed state

That is why this form is very natural for prepared items, arrangements, and setups.

In this sentence, the idea is:

• The ingredients have been placed next to the pot and are there ready for use.

This is a very common question.

置いてある

Focuses on the resulting state of something that was intentionally placed there.

• 材料が鍋の横に置いてある。
• The ingredients have been placed next to the pot.

This sounds like someone set them there on purpose.

置いている

Can describe an ongoing action or a state, depending on context, but it often sounds more neutral and less specifically like a prepared result.

• 私は材料を鍋の横に置いている。
• I am putting / I keep the ingredients next to the pot.

With objects, 〜てある is especially common when you want to emphasize that something is arranged in advance for a purpose.

Because に marks the location where something exists or has been placed.

• 鍋の横に置いてある = is placed next to the pot

Here, the ingredients are located there.

If you used で, it would suggest the place where an action happens:

• 鍋の横で切る = cut it next to the pot

So:

• に = location of existence/resulting placement
• で = location where an action is performed

横 means side or beside.

• 鍋の横 = the side of the pot / next to the pot

It is very natural for physical objects.

It is similar to 隣, but not exactly the same:

• 横 emphasizes the side position
• 隣 means neighboring/next to, often as a neighboring space or item

For objects, both can sometimes work, but 横 feels very natural here because the ingredients are physically placed beside the pot.

Yes, the person who placed them is not stated.

Japanese often leaves out information that is obvious or unimportant. In this sentence, the important point is not who did it, but the state of the ingredients now.

So the sentence means something like:

• The ingredients for tonight’s curry are already set next to the pot.

It does not matter whether I, you, Mom, or someone else placed them there.

Because 材料 refers to things, not living beings.

In Japanese:

• ある is used for inanimate things
• いる is used for people and animals

Since curry ingredients are objects, ある is the correct verb.

That is also why the pattern is 置いてある, not 置いている in the sense of being there as objects arranged in a certain state.

It can be understood as plural in English: ingredients.

Japanese nouns usually do not change form for singular vs. plural. So:

• 材料 can mean ingredient or ingredients
• context tells you which is meant

In this sentence, it naturally means ingredients, because curry usually needs multiple items.

No. Normal Japanese writing would usually be:

今夜のカレーの材料はもう鍋の横に置いてある。

The spaces in your version are just for learning purposes, to make the parts easier to see.

Yes, very strongly.

Because of もう and especially 置いてある, the sentence suggests that the ingredients are not just randomly there. They have been intentionally placed next to the pot, probably in preparation for making the curry.

So the nuance is something like:

• The ingredients for tonight’s curry are already set out next to the pot.

That set out feeling is an important part of 〜てある.