Veritas interdum dolorem affert, sed amicitiam servat.

Because veritas is in the nominative singular, which is the case typically used for the subject of a Latin sentence. It is the thing doing the actions affert and servat.

So in this sentence:

• veritas = truth
• it is what brings pain and preserves friendship

They are in the accusative singular because they are the direct objects of the verbs.

• affert = brings
• what does truth bring? dolorem = pain
• servat = preserves / keeps
• what does truth preserve? amicitiam = friendship

So:

• dolorem is the object of affert
• amicitiam is the object of servat

Interdum means sometimes or at times. It is an adverb, so it modifies the verb phrase rather than a noun.

Here it tells us that truth does not always bring pain, but sometimes does.

Latin adverbs often have flexible placement, so interdum could appear in different places without changing the basic meaning much.

They are third person singular present active indicative forms, because the subject veritas is singular.

• affert = he/she/it brings
• servat = he/she/it preserves

Since veritas is a singular noun, the verbs must also be singular: truth brings, truth preserves.

Classical Latin has no articles like English the, a, or an.

So:

• veritas can mean truth or the truth
• dolorem can mean pain or a pain
• amicitiam can mean friendship or a friendship

Which English article fits best depends on context and style.

Latin word order is much freer than English word order because the endings show how the words function in the sentence.

English depends heavily on position:

• Truth brings pain

Latin can move words around more easily because the cases and verb endings already show the relationships.

So Veritas interdum dolorem affert, sed amicitiam servat is natural Latin, even though it does not exactly match the most basic English pattern word-for-word.

The sentence is still easy to understand because:

• veritas is nominative
• dolorem and amicitiam are accusative
• affert and servat are finite verbs

Sed means but.

It connects the two ideas:

• truth sometimes brings pain
• but it preserves friendship

So sed marks a contrast between something unpleasant and something positive.

Yes, veritas is a feminine noun.

Its dictionary form is usually given as:

• veritas, veritatis = truth

In this sentence, its gender does not change the English translation very much, because English usually says truth rather than she. But in Latin, the gender matters for agreement with adjectives or pronouns if any are added.

For example, if an adjective described veritas, that adjective would need feminine agreement.

Yes. Affert comes from afferre, which is a compound of ad- + ferre.

• ferre = to carry, bear
• afferre = to bring, carry to

So affert literally has the sense of brings to or brings.

This is useful because many common Latin verbs are compounds of ferre.

No. In this sentence, servat means preserves, keeps, or maintains.

It comes from servare, which often means:

• to save
• to preserve
• to keep
• to protect

So amicitiam servat means that truth preserves friendship or keeps friendship intact, not that truth serves friendship in the English sense of doing service for it.

Yes. That is exactly what is happening.

Latin often does not repeat the subject when the same subject continues with another verb. After veritas ... affert, the verb servat is understood to have the same subject: veritas.

So the sentence means:

• Truth sometimes brings pain, but truth preserves friendship

But Latin naturally says it more elegantly without repeating the noun.

A learner might parse them like this:

• veritas → veritas, veritatis (f.) = truth
• interdum = sometimes
• dolorem → dolor, doloris (m.) = pain
• affert → afferre, affero, attuli, allatum = to bring
• sed = but
• amicitiam → amicitia, amicitiae (f.) = friendship
• servat → servare, servo, servavi, servatum = to preserve / keep

Knowing the dictionary forms helps explain the endings you see in the sentence.