byouin he iku mae ni, hokensyou wo kaban ni irete okimasu.

With 前に, Japanese uses the plain non-past form of the verb:

• 行く前に = before going
• 食べる前に = before eating

So 行った前に is not the pattern. The idea is that the action of going has not happened yet at that point.

Because verbs can directly modify nouns in Japanese.

Here, 前 is a noun, and 行く modifies it directly:

• 行く前 = the time before going

You use の after nouns, not after verbs:

• 食事の前に = before the meal
• 病院の前 = in front of the hospital

So:

• 行く前に is correct
• 行くの前に is not correct here

Here it means before, not front.

• 病院へ行く前に = before going to the hospital

If you wanted in front of the hospital, you would say:

• 病院の前に

So the grammar around 前 tells you which meaning it has.

Yes, に would also be natural here.

With movement verbs like 行く, both へ and に can mark the destination:

• 病院へ行く
• 病院に行く

The difference is small:

• へ emphasizes direction, as in toward
• に emphasizes the destination itself

In everyday Japanese, they are often very close in meaning in sentences like this.

Because 保険証 is the direct object of 入れる.

入れる means to put in, so the thing being put in takes を:

• 保険証を入れる = put in the insurance card
• 本を入れる = put in a book

So を marks what is being put into the bag.

Because に marks the destination or target location of 入れる.

With 入れる, the pattern is:

• A を B に 入れる
• put A into B

So here:

• 保険証を かばんに 入れる
• put the insurance card into the bag

The bag is the place the card goes into, so it takes に.

Because 入れて is the て-form, and it connects to おきます.

The full pattern is:

• 入れておきます

This is built from:

• 入れる = to put in
• 入れて = te-form
• おく / おきます = to do in advance, or to leave something that way

So 入れて is necessary because おく attaches to the て-form of the main verb.

〜ておきます usually means do something in advance for later convenience or preparation.

So:

• 保険証をかばんに入れておきます means
• put the insurance card in the bag ahead of time

It gives a feeling of preparation: you are doing it now so that it will be ready later.

This pattern can also sometimes mean leave something as it is, but in this sentence the main meaning is clearly prepare in advance.

入れます simply means put it in.

入れておきます adds the nuance of doing it beforehand or making preparations.

So compare:

• 保険証をかばんに入れます
  I put the insurance card in the bag.

• 保険証をかばんに入れておきます
  I put the insurance card in the bag in advance, so it will be ready.

That extra preparation nuance is important.

Because Japanese often leaves out subjects and topics when they are obvious from context.

So this sentence could be understood as:

• 私は病院へ行く前に、保険証をかばんに入れておきます。

But if I is already understood, Japanese usually omits 私は.

This is very normal and natural.

おきます is the polite ます-form of おく.

So:

• 入れておく = casual/plain
• 入れておきます = polite

The sentence is written in polite style, which is common in textbook examples and everyday respectful speech.

Also, this ます-form is non-past, so depending on context it can mean:

• a future action: I will put it in beforehand
• a habitual action: I put it in beforehand

The comma marks a natural pause after the time phrase:

• 病院へ行く前に、 ...

It helps separate the setup from the main action:

• Before going to the hospital,
• I put the insurance card in my bag in advance.

The comma is helpful, but it is not always absolutely required in Japanese.

No. Standard Japanese normally does not put spaces between words.

So this would usually be written as:

• 病院へ行く前に、保険証をかばんに入れておきます。

Spaces are often added in beginner materials to make the sentence easier to read.