Saimme lopulta tietää totuuden.

Saimme is the 1st person plural past tense form of saada.

So:

• saada = to get, receive, obtain; in some contexts also to be allowed to or to manage to
• saimme = we got / we received / we managed to

In this sentence, it is part of the expression saada tietää, which means to find out or to come to know.

A rough breakdown is:

• sai- = past tense stem
• -mme = we

So the verb itself already tells you the subject is we.

Because after saada, Finnish often uses another verb in the basic infinitive.

So:

• saimme tietää = literally something like we got to know
• natural English: we found out

This is a very common Finnish pattern:

• sain nähdä = I got to see
• saimme kuulla = we got to hear
• saitte oppia = you all got to learn

So tietää stays in the infinitive because saimme is the verb that carries the tense and person information.

It is both understandable literally and very commonly used as a set expression.

Saada tietää usually means:

• to find out
• to learn
• to come to know

So even though the parts are transparent, learners should treat saada tietää as a very natural Finnish way to express finding something out.

For example:

• Sain tietää asiasta eilen. = I found out about it yesterday.
• Milloin sait tietää totuuden? = When did you find out the truth?

Because tiesimme means we knew, not we found out.

This is an important difference:

• tiesimme = we knew
• saimme tietää = we found out / we came to know

So:

• Tiesimme totuuden. = We knew the truth.
• Saimme tietää totuuden. = We found out the truth.

The Finnish sentence is describing the moment or result of learning the truth, not the state of already knowing it.

Totuuden is the genitive-form object of totuus.

Here is the basic contrast:

• totuus = truth
• totuuden = the truth, as a completed whole object
• totuutta = truth, as a partial / incomplete / ongoing / indefinite object

In this sentence, the action is completed: we found out the whole truth. That is why Finnish uses the total object, which in the singular usually looks like the genitive form.

So:

• Saimme tietää totuuden. = We found out the truth.
  
  • completed result
• Saimme tietää totuutta vähän kerrallaan. = We learned the truth little by little.
  
  • more partial or unbounded sense

In practical learning terms, the form you see here is genitive-looking, and that is the safest way to think about it at first.

For many singular objects in Finnish, the total object takes the same form as the genitive:

• kirja → kirjan
• totuus → totuuden

So in this sentence, it is best to say:

• totuuden is the total object
• its form is the same as the genitive singular

If you go deeper into Finnish grammar, you may meet discussions of accusative object function, but for a learner, the important point is:

• completed whole object → totuuden
• partial / negated object → totuutta

Lopulta means something like:

• finally
• eventually
• in the end

In this sentence, it suggests that it took some time, or that there was some delay before the truth became known.

So the nuance is:

• Saimme lopulta tietää totuuden. = We finally / eventually found out the truth.

It often carries the feeling of after waiting, uncertainty, or a long process.

Because Finnish usually does not need subject pronouns when the verb ending already shows the person.

Here:

• saimme already means we got / we found out

So me is unnecessary unless you want emphasis or contrast.

Compare:

• Saimme lopulta tietää totuuden. = We finally found out the truth.
• Me saimme lopulta tietää totuuden. = We finally found out the truth.
  
  • more emphasis on we

This is very normal in Finnish: the verb ending often does the job that English subject pronouns must do.

Yes. Finnish word order is quite flexible, and changing it usually changes the focus or emphasis, not the core meaning.

For example:

• Saimme lopulta tietää totuuden.
  
  • neutral
• Lopulta saimme tietää totuuden.
  
  • stronger emphasis on finally / in the end
• Totuuden saimme lopulta tietää.
  
  • marked style; emphasizes the truth

The version you were given is a very natural, standard sentence.

Finnish has no articles like English a or the.

So totuus can mean:

• truth
• the truth

The exact meaning depends on context.

In this sentence, English naturally uses the truth, and Finnish shows that idea without an article:

• totuuden = the truth

So learners should get used to the fact that Finnish usually leaves definiteness to be understood from context.

Not necessarily.

Saimme tietää totuuden only says that we came to know the truth. It does not specify how.

That could mean:

• someone told us
• we discovered it ourselves
• we figured it out
• we read or heard it somewhere

If Finnish wanted to say specifically that someone told us, it would use a different structure, for example:

• He kertoivat meille totuuden. = They told us the truth.
• Meille kerrottiin totuus. = We were told the truth.

So saimme tietää is broader: the result is that we found out, but the source is left unstated.