tomodati ni sayonara wo itta.

It is read:

ともだち に さよなら を いった
tomodachi ni sayonara o itta

A couple of notes:

• 友達 = ともだち
• 言った is the past plain form of 言う and is read いった
• In normal writing, Japanese usually does not use spaces. The spaces here are just to make the sentence easier for learners to read.

に marks the target or person toward whom the action is directed.

So in this sentence:

• 友達に = to a friend
• さよならを言った = said goodbye

Together, 友達にさよならを言った means said goodbye to a friend.

This use of に is very common with verbs of speaking or giving, such as:

• 先生に聞いた = asked the teacher
• 母に手紙を書いた = wrote a letter to my mother

Because 言う often takes the thing being said as its direct object.

So:

• さよなら = goodbye
• さよならを言う = to say goodbye

Here, を marks what was said.

This pattern is similar to:

• 名前を言う = say one’s name
• 本当のことを言う = tell the truth

So the structure is basically:

• 友達に = to a friend
• さよならを = goodbye
• 言った = said

Because Japanese normally puts the main verb at the end of the sentence.

So even though English says:

• I said goodbye to my friend

Japanese is structured more like:

• To my friend goodbye said

That is normal Japanese word order.

In this sentence:

• 友達に comes first
• さよならを comes next
• 言った comes at the end

The subject is omitted.

Japanese often leaves out subjects when they are understood from context. So 友達にさよならを言った could mean:

• I said goodbye to my friend
• He said goodbye to his friend
• She said goodbye to her friend
• etc.

The listener usually figures it out from the situation or previous conversation.

This is one of the most common features of Japanese, and it can feel strange at first to English speakers because English usually requires an explicit subject.

言った is the plain past form of 言う.

• 言う = say
• 言った = said

If you want to make it polite, you would say:

• 友達にさよならを言いました

So the difference is mainly style / politeness:

• 言った = plain, casual
• 言いました = polite

The basic meaning stays the same.

Grammatically, the sentence is perfectly fine. But in real life, さよなら can sound a bit stronger or more final than English bye.

Depending on the situation, Japanese speakers often use other expressions more often, such as:

• じゃあね
• またね
• バイバイ
• 失礼します in more formal situations

さよなら is natural when you really are saying goodbye, but it can sometimes sound a little formal, textbook-like, or emotionally final depending on context.

So this sentence is correct, but in everyday conversation the exact expression might change.

Yes, that is possible in casual Japanese.

• 友達にさよならを言った
• 友達にさよならした

Both can mean said goodbye to a friend.

The version with 言う is more literally said goodbye, while さよならする treats さよなら almost like a verbal action by itself.

Learners will often first see さよならを言う because it clearly shows how the sentence is built, but さよならした is also natural.

Not in this sentence.

に is the correct particle because the friend is the target of the goodbye.

• 友達にさよならを言った = said goodbye to a friend

If you used と, it would not express the same relationship correctly here. と often means:

• with
• and
• or marks a quoted statement

So for this sentence, に is the natural choice.

Japanese word order is somewhat flexible, as long as the particles make the roles clear.

So these can all work:

• 友達にさよならを言った
• さよならを友達に言った

But 友達にさよならを言った is the most straightforward and natural basic order.

Even when word order changes, the verb usually still comes at the end.

By itself, 友達 just means friend or friends, depending on context.

In this sentence, it could mean:

• a friend
• my friend
• the friend
• sometimes even friends, if context supports that

Japanese often does not mark a / the / my as explicitly as English does. Context tells you which interpretation is best.

So 友達に is often translated as to my friend or to a friend, depending on the situation.

Because 言った is the standard past plain form of 言う.

This is an irregular-looking but very common conjugation pattern:

• 言う → 言った
• 買う → 買った
• 会う → 会った

Many -う verbs form the past this way.

So you should learn:

• dictionary form: 言う
• past plain form: 言った
• polite past form: 言いました

Usually, yes, or at least it strongly suggests that they expressed goodbye in words.

It is more specific than just left or parted. It focuses on the act of saying farewell.

So:

• 友達にさよならを言った = said goodbye to a friend

If you wanted to talk more generally about parting ways, a different expression might be used depending on context. This sentence specifically centers on the spoken farewell.