Älä valehtele minulle.

Älä is the special negative word used for the 2nd person singular imperative, meaning don’t ...!

So:

• Älä valehtele. = Don’t lie.

Finnish does not use ei here, because ei is the normal negative verb for statements, not for commands.

Compare:

• Et valehtele. = You are not lying. / You do not lie.
• Älä valehtele. = Don’t lie.

So älä tells you this is a command/request in the negative.

Yes, the dictionary form is valehdella, meaning to lie.

In Älä valehtele, the form valehtele is the verb form used after the negative imperative älä.

A useful way to think about it is:

• dictionary form: valehdella = to lie
• command: Valehtele! = Lie!
• negative command: Älä valehtele! = Don’t lie!

So after älä, Finnish uses the verb in this special command-related form, not in the infinitive.

Yes. Minulle literally means to me.

It comes from minä = I, and the form minulle is the allative case, which often expresses movement or direction to someone or something, and is also used in many situations where English says to someone.

So:

• Älä valehtele minulle. = Don’t lie to me.

This is very natural Finnish. With valehdella, the person being lied to is commonly marked this way:

• minulle = to me
• sinulle = to you
• hänelle = to him/her
• meille = to us

Because Finnish usually leaves the subject out when it is already clear from the verb form or sentence type.

Here, älä already shows that the command is directed at one person: you.

So Finnish does not need sinä here.

• Älä valehtele minulle. = Don’t lie to me.

You could add sinä for special emphasis, but normally you would not.

Yes, Älä valehtele minulle is addressed to one person informally.

If you want to say Don’t lie to me to more than one person, or in the formal/polite way to one person, you use:

• Älkää valehdelko minulle.

So:

• Älä valehtele minulle. = singular informal
• Älkää valehdelko minulle. = plural or formal/polite

This is a very common Finnish pattern in commands.

Yes, but Älä valehtele minulle is the most neutral and natural order.

Finnish word order is fairly flexible, and changing it often changes the emphasis, not the basic meaning.

For example:

• Älä valehtele minulle. = neutral
• Minulle älä valehtele. = Don’t lie to me (maybe lie to others if you must, but not to me)
• Älä minulle valehtele. = also emphatic, often emotional

So the original sentence is the safest standard version.

A simple pronunciation guide:

• Älä ≈ AH-lah, but with ä pronounced like the vowel in cat for many English speakers
• valehtele ≈ VAH-leh-teh-leh
• minulle ≈ MEE-nool-leh

A few key points:

• Stress in Finnish is usually on the first syllable:
  • Älä
  • VAlehtele
  • MInulle
• Double consonants are pronounced longer:
  • minulle has ll, so hold the l a bit longer
• Finnish vowels are pronounced clearly and consistently; they do not reduce as much as in English

Minulle is the standard written form.

In everyday spoken Finnish, many speakers say:

• Älä valehtele mulle.

Here:

• minulle = standard / careful form
• mulle = common spoken form

Both mean the same thing: to me.

If you are learning standard Finnish, use minulle first. It is always correct in writing.

By itself, it is a direct negative imperative, so it usually sounds like a clear command:

• Don’t lie to me.

How strong it feels depends a lot on context, tone of voice, and relationship between the speakers.

If you want to sound softer, Finnish often uses extra words or a different structure, for example:

• Älä nyt valehtele minulle. = Now don’t lie to me.
• Ethän valehtele minulle? = You’re not lying to me, are you?

So the basic sentence is direct, but Finnish has many ways to make the tone gentler, more emotional, or more accusatory.

Finnish does not have articles like English a/an or the.

So Finnish simply says:

• Älä valehtele minulle.

There is no need to add anything corresponding to the or a. This is normal in Finnish grammar, not something special about this sentence.