kizi wo teppan ni nagaku oku to, kogeru.

A natural breakdown is:

• 生地（きじ） = dough, batter, or pastry/cloth material depending on context
  
  • In a cooking sentence like this, it means dough/batter
• を = marks the direct object
• 鉄板（てっぱん） = iron plate, griddle, hot plate
• に = marks the place where something is put
• 長く = for a long time; long
  
  • here it is the adverb form of 長い
• 置く（おく） = to put; to leave
• と = if / when
• 焦げる（こげる） = to burn, to get scorched

So the sentence structure is basically: If you leave the batter on the griddle for too long, it burns.

Because 生地 is the thing being acted on by 置く.

In 生地を置く, the batter/dough is what you place or leave, so it takes を, the direct object marker.

Compare:

• 本を置く = put a book down
• 皿を置く = place a plate
• 生地を置く = place the batter/dough

So を tells you what is being put on the griddle.

Because に marks the location where something is placed.

With 置く, the common pattern is:

• A を B に 置く
  = put A on/in/at B

So here:

• 生地を鉄板に置く
  = put the batter on the griddle

You can think of に here as marking the destination or resting place of the object.

Because 長く is the adverb form of 長い.

• 長い = long
• 長く = long / for a long time, used to modify a verb

Here, 長く modifies 置く, so it means:

• 長く置く = leave it for a long time / leave it too long

You cannot use 長い directly before 置く in this sentence, because 長い is an adjective form, not the adverb form needed to modify a verb.

Here it means for a long time.

Even though 長い often means something physically long, when its adverb form 長く modifies a verb like 置く, it often refers to duration.

So:

• 鉄板に長く置く = leave it on the griddle for a long time

It does not mean the batter is physically long.

No. This と is the conditional と, meaning if or when.

In this sentence:

• 生地を鉄板に長く置くと、焦げる。
• If/when you leave the batter on the griddle too long, it burns.

This is different from:

• A と B = A and B
• 友だちと行く = go with a friend

So the sentence uses the conditional と, not the and/with と.

The conditional と is often used for things that happen naturally, automatically, or as a general result.

So this sentence sounds like a general truth:

• If you leave batter on the griddle too long, it burns.

That fits と well because it describes a predictable consequence.

Very roughly:

• と = when/if X happens, Y naturally follows
• たら = if/when X happens, then...
• ば = if X, then Y
• なら = if it is the case that X / if you say X

Here, と is especially natural because burning is the expected result of leaving it too long.

Because 焦げる is intransitive, while 焦がす is transitive.

• 焦げる = to burn / get burnt
• 焦がす = to burn something / scorch something

In this sentence, the batter is presented as undergoing the change by itself:

• 生地が焦げる = the batter burns

If you used 焦がす, you would need someone or something as the doer:

• 私は生地を焦がした = I burned the batter

So 焦げる is correct here because the sentence is describing what happens to the batter.

Because Japanese often omits things that are clear from context.

The first part already mentions 生地, so in the second part, Japanese does not need to repeat it:

• 生地を鉄板に長く置くと、(生地が)焦げる。

The subject of 焦げる is understood to be 生地.

This kind of omission is very common in Japanese and can sound more natural than repeating the noun.

Because Japanese often leaves out subjects when they are obvious or unimportant.

English usually needs something like:

• If you leave it on the griddle too long, it burns.

Japanese often does not say you or it if the meaning is clear from context.

So the sentence is understood as something like:

• If you leave the batter on the griddle too long, it burns.

But Japanese does not need to explicitly say you.

置く means to place or to leave something somewhere, often with the idea that someone intentionally put it there.

So:

• 鉄板に置く = put it on the griddle
• 鉄板に長く置く = leave it on the griddle too long

By contrast:

• ある means to exist / be located for inanimate things

So 生地が鉄板にある would just mean the batter is on the griddle, not someone left it there too long.

置く is the better choice because the sentence is about the action of leaving it there.

It expresses a general fact or predictable result.

Japanese non-past forms like 置く and 焦げる do not only mean present tense. They can also express:

• present
• future
• habitual action
• general truths

Here the meaning is general:

• If you leave batter on the griddle too long, it burns.

So it is not describing just one specific event unless the context makes it specific.

Not always wrong, but it changes the feel.

The original sentence is a straightforward cause-and-result statement:

• 生地を鉄板に長く置くと、焦げる。

If you said:

• 生地は鉄板に長く置くと、焦げる。

that sounds less natural because 生地 is really the object of 置く, so を fits more directly.

You might hear other rephrasings, such as:

• 生地は鉄板に長く置くと焦げる。

but the original 生地を is the most straightforward match with 置く.

So learners should usually understand the original as the normal pattern:

• thing + を + place + に + 置く

They are:

• 生地 = きじ
• 鉄板 = てっぱん
• 長く = ながく
• 置く = おく
• 焦げる = こげる

A full reading is:

• きじ を てっぱん に ながく おく と、こげる。

One thing to watch out for is 生地, because in other contexts it can have different meanings, but in cooking it is commonly read きじ and means dough/batter.