namae wo ookiku kaite kudasai.

を marks the direct object of the verb.

In this sentence, the verb is 書いてください (please write), and the thing being written is 名前 (name). So:

• 名前を = the name as the thing to write

A very literal breakdown is:

• 名前 = name
• を = object marker
• 大きく = largely / in a big way
• 書いてください = please write

So 名前を tells you what should be written.

Because 大きい is an i-adjective, and when an i-adjective modifies a verb, it usually changes to its -く form.

Here, 大きく describes how you should write, so it works like an adverb:

• 大きい = big
• 大きく = bigly / in a big way → more naturally, largely or in large letters

So:

• 大きい名前 = a big name
• 名前を大きく書く = to write the name big

This is a very common pattern:

• 早い → 早く
• 小さい → 小さく
• きれいだ is different, because it is a na-adjective

Yes. In this sentence, 大きく is functioning adverbially.

It tells you how the action is done:

• 書く = write
• 大きく書く = write big / write in large letters

So even though 大きい is an adjective in dictionary form, its -く form often works like an adverb.

書いてください is:

• the て-form of 書く → 書いて
• plus ください

This pattern means please do X.

So:

• 書く = to write
• 書いて = write... / writing...
• 書いてください = please write

It is a standard polite request pattern in Japanese.

The dictionary form is 書く (to write).

The て-form is 書いて. This form is used in many grammar patterns, including:

• 書いてください = please write
• 書いています = is writing / writes
• 書いてもいいです = may write
• 書いてはいけません = must not write

So in this sentence, 書いて is not random; it is the て-form of 書く.

Japanese word order is different from English.

English often puts the verb earlier:

• Please write your name in large letters.

Japanese usually puts the main verb at the end:

• 名前を = name
• 大きく = big / in large letters
• 書いてください = please write

A useful rule is:

• the verb comes last
• words that describe the action usually come before the verb

So 大きく comes before 書いてください because it describes how the writing should be done.

The subject is omitted because Japanese often leaves out information that is obvious from context.

In a sentence like this, the speaker is usually asking the listener to do it. So the implied meaning is something like:

• (You), please write your name in large letters.

Japanese often omits:

• you
• I
• it
• my / your / his / her

if the context already makes them clear.

That is why your is not explicitly stated in the Japanese sentence, even though it may be understood in context.

Yes, but it has a different nuance.

• 名前を大きく書いてください is the most straightforward way to say Please write your name large.
• 名前は大きく書いてください gives special focus to the name, as in:
  • As for the name, please write it large
  • maybe implying contrast with something else

For example, if a form has several items, someone might say:

• 住所は普通に書いて、名前は大きく書いてください。
• Write the address normally, but write the name large.

So を is neutral and direct, while は often adds contrast or topic focus.

It can mean either, depending on context.

Common possibilities include:

• handwriting in bigger letters
• printing in a larger size
• writing something so it stands out more

In a paper form, it usually means write it in large letters. On a computer, the exact interpretation would depend on the situation, but the basic idea is still make the writing large.

It is a polite request, not a harsh command.

• 書いてください = please write
• 書け = write! (strong, blunt command)
• 書いて = write / please write, depending on tone and context

So 書いてください is a normal polite way to tell someone to do something, often used in instructions, forms, signs, and everyday speech.

Because 大きい cannot directly modify the verb 書く in that form.

If you want to describe how something is written, you need the adverbial form:

• 大きい → adjective form
• 大きく → adverbial form

So:

• 大きい字 = big letters
• 字を大きく書いてください = please write the letters big

That is why 大きく書いてください is correct, and 大きい書いてください is not.