Не лги мне, пожалуйста.

A word-by-word breakdown is:

• Не = not / don’t
• лги = lie in the imperative form, addressed to one person informally
• мне = to me
• пожалуйста = please

So the literal structure is:

• Не лги = Don’t lie
• мне = to me
• пожалуйста = please

That gives Don’t lie to me, please.

Because лгать is not a regular verb in the imperative.

Its forms are irregular enough that you really have to learn them as a set:

• лгать = to lie
• я лгу = I lie
• ты лжёшь = you lie
• они лгут = they lie
• лги! = lie! / don’t lie!

So лги is the correct imperative singular form.

This is one of those verbs where Russian does not form the command in the way an English speaker might first expect.

Лги is the imperative singular form of лгать.

That means it is used when you are telling one person what to do or not do, in an informal way:

• Лги мне. = Lie to me.
• Не лги мне. = Don’t lie to me.

If you were speaking to:

• more than one person, or
• one person formally

you would use лгите:

• Не лгите мне, пожалуйста.

Because Russian usually does not need to say the subject pronoun in commands.

In English, we say:

• Don’t lie to me.

The you is understood, even though it is not spoken.

Russian works the same way here:

• Не лги мне.

The verb form лги already shows that this is a command to you.

You can add ты or вы for extra emphasis, but normally you do not:

• Ты не лги мне. = You, don’t lie to me.
  This sounds more emphatic.

Because after лгать, Russian uses the dative case for the person being lied to.

The question is:

• лгать кому? = to lie to whom?

So:

• мне = to me
• ему = to him
• ей = to her
• нам = to us

Examples:

• Не лги мне. = Don’t lie to me.
• Он лжёт ей. = He lies to her.

So мне is correct because the verb requires the dative here.

That is the normal way Russian makes a negative command:

• не + imperative

Examples:

• Не говори. = Don’t speak.
• Не уходи. = Don’t leave.
• Не лги. = Don’t lie.

English needs don’t, but Russian simply puts не before the imperative verb.

This gets into both aspect and word choice.

1. лги vs солги

Лгать is imperfective, and Russian commonly uses the imperfective in negative imperatives for a general prohibition:

• Не лги мне. = Don’t lie to me. / Don’t be lying to me.

This sounds like a general request or rule.

A perfective form such as солгать would point more to one completed lie:

• Не солги мне would mean something more like Don’t tell me a lie or Be careful not to lie to me once

That is usually not the most natural choice for a general don’t lie statement.

2. лгать vs врать

Both can mean to lie, but:

• лгать often sounds a bit more neutral or bookish
• врать is very common in everyday speech and can sound more conversational

So in daily speech, many people would also say:

• Не ври мне, пожалуйста.

That is very natural too.

Yes, it is grammatical and natural.

That said, many native speakers in everyday conversation would probably say:

• Не ври мне, пожалуйста.

This is because врать is very common in spoken Russian.

So the sentence you have is good, but it may sound a little more careful, literary, or less colloquial than Не ври мне, пожалуйста.

Пожалуйста is very flexible in Russian. It can appear in different places:

• Не лги мне, пожалуйста.
• Пожалуйста, не лги мне.
• Не лги, пожалуйста.

All of these are possible.

Putting пожалуйста at the end is a very common way to soften a request or command.

As for the comma: пожалуйста is usually treated as a parenthetical politeness word in sentences like this, so it is set off with a comma:

• Не лги мне, пожалуйста.
• Пожалуйста, не лги мне.

Yes. Russian word order is flexible, and changing it usually changes the emphasis, not the basic meaning.

The neutral version is:

• Не лги мне, пожалуйста.

If you say:

• Мне не лги, пожалуйста.

you are emphasizing мне — as if meaning Don’t lie to me in particular.

So the original sentence is the most neutral and straightforward order.

You change the imperative from лги to лгите:

• Не лгите мне, пожалуйста.

This is used for:

• formal singular (you = вы)
• plural (you all)

So:

• Не лги мне = informal, one person
• Не лгите мне = formal one person or multiple people

A learner-friendly approximation is:

• nye lgee mnye pa-ZHA-luh-sta

A few notes:

• лги is only one syllable, so it is automatically stressed.
• мне sounds roughly like mnye
• пожалуйста is stressed on жа: пожа́луйста

The trickiest part for many English speakers is лги, because the consonant cluster at the start is unusual. It helps to practice it slowly:

• лги
• не лги
• не лги мне