Spune-mi adevărul acum.

Spune-mi is made of two parts:

• spune = tell / say (imperative form of a spune)
• mi = to me

So Spune-mi literally means Tell me.

The hyphen is used because mi is a short unstressed pronoun clitic, and in an affirmative command it attaches to the verb:

• Spune-mi = Tell me
• Dă-mi = Give me
• Arată-mi = Show me

Because mi means to me, while mă means me as a direct object.

With a spune, the person receiving the information is normally an indirect object:

• Spune-mi adevărul = Tell me the truth

Compare:

• mă vede = he/she sees me → direct object
• îmi spune / mi spune = he/she tells me → indirect object

So in this sentence, mi is the correct form.

Mi is the normal unstressed clitic form, and it is what you usually use with the verb.

• Spune-mi adevărul. = normal, natural
• Spune-mi mie adevărul. = more emphatic, like Tell me the truth

So mie can appear, but usually only for emphasis or contrast. In everyday Romanian, mi alone is enough here.

Because Romanian usually puts the definite article at the end of the noun.

• adevăr = truth / a truth
• adevărul = the truth

So:

• Spune-mi adevărul = Tell me the truth

This is one of the most important features of Romanian grammar: the definite article is attached to the noun instead of being a separate word like English the.

Acum is an adverb meaning now.

In this sentence, it comes at the end because that is a very natural Romanian word order:

• Spune-mi adevărul acum.

But Romanian word order is fairly flexible, so you may also hear:

• Acum spune-mi adevărul.
• Spune-mi acum adevărul.

These versions are all possible, but they can shift the emphasis a little. The version with acum at the end sounds straightforward and natural.

No. Here spune is the imperative singular, used to give a command.

The verb is a spune = to say / to tell.

In this sentence:

• spune = tell! (said to one person, informal)

So Spune-mi adevărul acum. is a command directed at one person.

You would use the plural/polite imperative:

• Spuneți-mi adevărul acum.

This can mean:

• Tell me the truth now. (to several people)
• Tell me the truth now. (to one person, politely)

So:

• Spune-mi = informal singular
• Spuneți-mi = plural or polite singular

Yes, but the meaning changes.

• Spune-mi adevărul acum. = Tell me the truth now.
• Spune adevărul acum. = Tell the truth now. / Say the truth now.

Without mi, the sentence no longer includes to me. So if you want tell me, you need mi.

Yes. In Spune-mi adevărul acum:

• spune = verb
• mi = indirect object (to me)
• adevărul = direct object (the truth)
• acum = adverb (now)

So the structure is basically:

• Tell
  • me
    • the truth
      • now

In adevărul, the letter ă is pronounced like a schwa, similar to the a in English about.

So adevărul sounds roughly like:

• a-de-və-rul

A few useful notes:

• ă = a short neutral vowel, like uh
• rul at the end is pronounced clearly
• Romanian spelling is generally quite phonetic, so words are usually pronounced close to how they are written

By itself, it is a fairly direct command. It can sound:

• neutral and urgent in the right context
• forceful if spoken sharply
• rude if used in the wrong situation

Because it is an imperative, tone matters a lot. If you want to sound softer, Romanian often uses other structures, for example:

• Te rog, spune-mi adevărul acum. = Please tell me the truth now.

So the sentence itself is grammatically neutral, but pragmatically it is quite direct.