Wy czytacie lepiej wieczorem.

Wy means you plural — you all / you guys / you (more than one person).

In modern standard Polish, wy is normally not used for one person. For formal singular you, Polish uses Pan or Pani with a 3rd-person verb form, for example:

• Pan czyta
• Pani czyta

So Wy czytacie lepiej wieczorem is addressing more than one person.

It can often be left out.

Polish usually drops subject pronouns when the verb ending already shows who the subject is. The ending -cie in czytacie already tells us it means you plural.

So both are possible:

• Wy czytacie lepiej wieczorem.
• Czytacie lepiej wieczorem.

Adding wy gives extra emphasis, for example:

• You read better in the evening.
• As for you, you read better in the evening.

It can sound contrastive, as if comparing you with someone else.

Czytacie is the 2nd person plural present tense of czytać (to read).

A quick breakdown:

• czytać = to read
• czyta- = verb stem
• -cie = ending for you plural

So:

• ja czytam = I read / am reading
• ty czytasz = you read / are reading
• on/ona czyta = he/she reads
• my czytamy = we read
• wy czytacie = you (plural) read
• oni/one czytają = they read

It can, in principle, mean either, because Polish does not have a separate present continuous form like English am reading.

So czytacie can mean:

• you read
• you are reading

However, in this sentence, the most natural meaning is habitual/general:

• You read better in the evening.

That is because wieczorem (in the evening) often describes a general time when something usually happens.

Because lepiej is the comparative adverb meaning better.

Here it describes how the action is done:

• czytacie lepiej = you read better

Compare:

• dobrze = well
• lepiej = better

But lepszy is an adjective, not an adverb. It would describe a noun, not a verb.

For example:

• To jest lepsza książka. = That is a better book.

So:

• czytacie lepiej = correct
• czytacie lepszy = incorrect

Wieczorem comes from the noun wieczór (evening), and here it is in the instrumental singular form.

• wieczór = evening
• wieczorem = in the evening

In Polish, some time expressions use the instrumental case adverbially. So wieczorem functions like an adverb of time.

Very common examples:

• rano = in the morning
• nocą = at night
• wieczorem = in the evening

So you do not need to translate it word-for-word as a regular noun phrase. In this sentence, it simply means in the evening.

Because this sentence describes a general ability/habit, not a completed action.

Czytać is imperfective, which is the normal choice for:

• repeated actions
• habits
• general statements
• actions in progress

So Wy czytacie lepiej wieczorem means something like:

• you generally read better in the evening
• you tend to read better in the evening

A perfective verb such as przeczytać usually focuses on completing something, for example to read through / to finish reading. That would not fit as naturally here.

Yes. Polish word order is flexible, and changing it often changes emphasis, not the core meaning.

For example:

• Wy czytacie lepiej wieczorem.
  Emphasis on you.

• Czytacie lepiej wieczorem.
  Neutral and very natural.

• Wieczorem czytacie lepiej.
  Emphasis on in the evening.

• Lepiej czytacie wieczorem.
  Emphasis on better.

English relies more on fixed word order, but Polish often uses word order to highlight what is most important in the sentence.

In many contexts, the most natural version would simply be:

• Czytacie lepiej wieczorem.

That is because Polish often omits the subject pronoun unless it is needed for contrast or emphasis.

If the speaker wants to stress you, then Wy czytacie lepiej wieczorem is also fine.

A rough English-friendly approximation is:

• czytacie ≈ chy-TA-cheh

But that is only approximate.

A few key points:

• cz sounds like ch in chop
• y is a Polish vowel that does not exist exactly in English
• ci before e sounds like a soft ch-like sound, roughly ć

So the whole sentence is approximately:

• Vih chih-TA-cheh LEH-pyey VYEH-cho-rem

Again, that is only a rough guide. The real Polish sounds are a bit different from English ones.

Usually it is written wy with a lowercase w.

Sometimes in letters, emails, or very polite direct address, people may capitalize pronouns like Ty, Wy, Wasz, etc. to show respect or formality. But that is a stylistic choice, not a grammar rule for ordinary sentences.

So in a normal sentence:

• Wy czytacie lepiej wieczorem.
  or more commonly
• Czytacie lepiej wieczorem.

both are standard.