henkou wo ukeiremasita.

It is pronounced:

へんこう を うけいれました
henkō o ukeiremashita

A couple of notes:

• 変更 = へんこう
• を is written wo, but in modern Japanese it is pronounced o
• 受け入れました = うけいれました

So the whole sentence sounds like:

henkō o ukeiremashita

変更 is a noun here. It means change, modification, or alteration, depending on context.

In this sentence, it is the thing being accepted.

Also, 変更 is a Sino-Japanese noun and can often appear in more formal or business-like contexts. Compared with a more everyday word like 変化, 変更 usually suggests a deliberate change or revision rather than a natural change.

を marks the direct object of the verb.

So in:

変更を受け入れました

the thing being accepted is 変更.

You can think of it like this:

• 変更 = the change
• を = marks the change as the object
• 受け入れました = accepted

So を is doing the job that English word order often does in a sentence like accepted the change.

The dictionary form is 受け入れる.

This is the plain, non-past form.
The sentence uses 受け入れました, which is the polite past form.

Breakdown:

• 受け入れる = dictionary form
• 受け入れます = polite non-past
• 受け入れました = polite past

So the sentence is using a polite style and says that the acceptance happened in the past or is viewed as completed.

It comes from the verb 受け入れる, which is an ichidan verb.

Formation:

• 受け入れる
• remove る → 受け入れ
• add ました → 受け入れました

So:

受け入れる → 受け入れました

This is the normal way to make the polite past form of an ichidan verb.

Usually, yes, but its nuance is worth noticing.

受け入れる literally combines:

• 受ける = to receive
• 入れる = to put in / let in

So it often gives the feeling of:

• accepting
• taking in
• admitting
• being willing to allow or adopt something

Depending on context, 受け入れる can be used for:

• accepting a proposal
• accepting a change
• accepting criticism
• taking in refugees
• admitting a patient or student

In this sentence, it suggests accepting the change in a fairly natural and standard way.

Because ました is the polite past ending.

So 受け入れました means the action has already happened, or the speaker is presenting it as completed.

Compare:

• 変更を受け入れます = will accept / accept
• 変更を受け入れました = accepted / have accepted

Japanese past tense does not always match English past tense perfectly, but here it clearly marks a completed action.

It could be either, depending on context.

Japanese nouns usually do not mark singular vs. plural the way English nouns do. So 変更 could mean:

• a change
• the change
• changes
• the changes

The surrounding context tells you which is most natural.

So even though English usually forces you to choose singular or plural, Japanese often leaves that open.

The subject is omitted.

This is extremely common in Japanese. If the subject is obvious from context, it is often left unstated.

So 変更を受け入れました could mean:

• I accepted the change
• We accepted the change
• They accepted the change
• The company accepted the change

Japanese often focuses on the action and object first, and leaves the listener to infer the subject from the situation.

Yes. It is in the polite style because of ました.

Compare:

• 変更を受け入れました = polite
• 変更を受け入れた = plain

The polite version is appropriate in many everyday, workplace, and formal situations.

No. Normally, Japanese is written without spaces.

So the natural written form is:

変更を受け入れました。

Spaces are often added only in learning materials to make it easier to see the parts of the sentence.

By itself, 変更 is mainly a noun, but it can also function as a verbal noun with する.

For example:

• 変更する = to change / to make a change
• 変更しました = changed / made a change

But in your sentence, 変更 is not the verb.
The main verb is 受け入れました.

So this sentence is not changed; it is accepted the change.

They describe different actions.

• 変更しました = made a change / changed something
• 変更を受け入れました = accepted a change

So:

• 変更しました means the person carried out the change
• 変更を受け入れました means the person agreed to it or allowed it

That difference is important.

Not in the same basic structure.

を marks 変更 as the direct object of 受け入れる, so it is the normal particle here.

• 変更を受け入れました = accepted the change

If you used は, you would be changing the function of 変更 and probably the whole sentence structure. For example, 変更は受け入れました sounds like As for the change, [someone] did accept it, with contrast or emphasis.

So を is the default and correct object marker here.

Yes. It is a compound verb made from:

• 受ける
• 入れる

Together, they form 受け入れる, which has its own established meaning: to accept, to admit, or to take in.

This is useful to know because many Japanese verbs are built this way, but you should still learn 受け入れる as one vocabulary item, since its meaning is not always just the sum of the two parts in a literal way.