Я ненавижу ложь.

Ненавижу is the 1st person singular form of the verb ненавидеть (to hate).

So:

• ненавидеть = to hate
• я ненавижу = I hate

This is a present-tense form, but with a verb like to hate, English also normally uses the simple present: I hate.

A few other forms of the same verb are:

• я ненавижу = I hate
• ты ненавидишь = you hate
• он / она ненавидит = he / she hates
• мы ненавидим = we hate

One thing learners often notice is that the stem changes a little:

• ненавидеть → ненавижу

That change is just part of how this verb conjugates.

Yes, it is in the accusative case.

The verb ненавидеть takes a direct object, so the thing being hated goes into the accusative:

• Я ненавижу ложь. = I hate lies / falsehood.

The reason ложь does not visibly change is that this noun belongs to a pattern where the nominative singular and accusative singular look the same.

So:

• nominative: ложь
• accusative: ложь

Even though the form looks unchanged, its role in the sentence is still accusative.

Ложь can mean several closely related things:

• a lie
• lies
• falsehood
• lying as a general concept

In this sentence, Я ненавижу ложь, it most naturally sounds like a general statement:

• I hate lies
• I hate falsehood
• I hate lying

So it is not necessarily talking about one specific lie. It is more like hating the whole idea or practice of lying.

Yes, absolutely.

Russian often omits subject pronouns when the verb form already makes the subject clear. Since ненавижу already means I hate, you can say:

• Ненавижу ложь.

This is very natural.

Including я can add emphasis or contrast:

• Я ненавижу ложь, а он к ней относится спокойно.
  I hate lies, but he is calm about them.

So:

• Я ненавижу ложь. = neutral or slightly emphatic
• Ненавижу ложь. = very natural, often more conversational

Because Russian does not have articles like English a / an / the.

So Russian simply says:

• Я ненавижу ложь.

And the exact English choice depends on context:

• I hate lies
• I hate lying
• I hate falsehood
• sometimes I hate a lie or I hate the lie, if context makes it specific

Russian leaves that kind of information to context rather than using articles.

The stress is:

• Я ненави́жу ложь.

A rough pronunciation guide:

• Я = ya
• ненави́жу = ni-na-VEE-zhu
• ложь = approximately losh

A few useful notes:

• The stress in ненавижу is on ви́.
• The final ь in ложь is not pronounced as a separate sound.
• At the end of the word, ж is devoiced in actual pronunciation, so ложь sounds closer to losh than lozh.

Great question. In ложь, the final ь is mostly a spelling and grammar marker, not a separately pronounced sound.

After letters like ж and ш, the soft sign often does not make the consonant sound soft in the usual way. Instead, it often helps show that the noun is:

• feminine
• part of a certain declension pattern

So the ь in ложь is important for grammar and spelling, even though you do not hear a clear extra sound for it.

Compare:

• нож = knife, masculine
• ложь = lie / falsehood, feminine

That final ь helps signal that ложь is a different kind of noun grammatically.

The normal, neutral order is:

• Я ненавижу ложь.

Russian word order is more flexible than English, so other orders are possible, but they change the emphasis.

For example:

• Ложь я ненавижу.
  As for lies, I hate them. / Lies are what I hate.

• Ненавижу я ложь.
  This can sound more emotional, marked, or contrastive.

So if you are just learning the sentence as a basic neutral statement, Я ненавижу ложь is the best version to remember.