Learn Hardcore Ukrainian: Будь ласка, напиши номер паспорта чітко. - Please write the passport number clearly.

The verb напиши is the informal second-person singular imperative, so you’re addressing one person you’d call ти (a friend, colleague, child). To be formal or to address more than one person, use Напишіть, будь ласка, номер паспорта чітко.

Why is there a comma after Будь ласка?

Будь ласка is a parenthetical politeness marker (“please”) and is set off with a comma when it comes at the beginning. If you put it mid-sentence, you usually set it off with commas on both sides; at the end, you put a comma before it:

Будь ласка, напиши номер паспорта чітко.
Напиши, будь ласка, номер паспорта чітко.
Напиши номер паспорта чітко, будь ласка.

Can I place будь ласка elsewhere in the sentence?

Yes. Beginning, middle, or end are all fine; just keep the commas as above. Avoid splitting the phrase itself; keep будь ласка together.

What’s the difference between напиши, напишіть, пиши, запиши, and впиши?

напиши: informal “write” (one action).
напишіть: formal/plural “write” (one action).
пиши/пишіть: “write” (ongoing or habitual; less natural for a one-off instruction).
запиши/запишіть: “write down / note down.”
впиши/впишіть: “enter (into a form/blank)”—best when there’s a specific field to fill in.

What exactly does чітко mean here? Would розбірливо be better?

чітко means “clearly, distinctly, precisely” (works for speech or writing). If you specifically mean “legibly (handwriting),” розбірливо is more precise:

Будь ласка, напиши номер паспорта розбірливо. For forms filled in by hand, you might also see:
Напишіть, будь ласка, номер паспорта друкованими літерами. (“in block letters”)

Why is it номер паспорта and not just номер паспорт?

Ukrainian uses the genitive case to show “of X.” It’s “number of passport,” so паспорт goes to genitive singular паспорта. This is a standard “X of Y” pattern: номер (чого?) паспорта.

Is паспорта a plural form here?

No. Here паспорта is genitive singular (“of the passport”). The normal Ukrainian nominative plural is паспорти. Avoid паспорта as a plural (that’s a Russian-only plural pattern).

How do I pronounce the sentence? Any tricky sounds?

Approximate transliteration: Budʹ laska, napyshy nomer pasporta chitko. Tips:

ь in будь softens the consonant: д is palatalized (like “d” with a light “y” glide).
и is a short, central vowel (like the i in “roses” or a relaxed “ih”), different from і (like “ee”).
ч = “ch,” ш = “sh,” х = hard “kh” (as in German “Bach”).
Stress to note: напиши is stressed on the last syllable; чітко and номер are stressed on the first syllable.

Do I need to say “your,” as in “your passport number”?

It’s usually understood from context with the imperative. If you want to be explicit, use свій:

Напиши, будь ласка, свій номер паспорта чітко.
Formal: Напишіть, будь ласка, свій номер паспорта чітко.

Is the word order fixed? Where can I put чітко?

Word order is flexible. Common options:

Будь ласка, напиши номер паспорта чітко. (neutral)
Чітко напиши номер паспорта, будь ласка. (emphasis on writing clearly)
Напиши, будь ласка, номер паспорта чітко. (polite, quite natural)

How would I phrase this for a more formal instruction on a form or sign?

Напишіть, будь ласка, номер паспорта розбірливо.
Вкажіть, будь ласка, номер документа.
Заповніть, будь ласка, поле Номер документа друкованими літерами.

Is будь ласка only “please,” or does it have other uses?

Besides “please,” будь ласка is also used as “you’re welcome” (reply to дякую) and “here you go” when handing something over.

Is паспортний номер acceptable for “passport number”?

It’s understandable but not the usual wording. The standard, especially in forms, is номер паспорта. For modern Ukrainian ID cards you’ll also see номер документа.