Onay kutusu görünmüyorsa sayfayı biraz daha aşağı kaydır.

Literally, onay means approval / confirmation, and kutusu means its box / box.

Together, onay kutusu is the standard Turkish term for a checkbox in a user interface.

• onay = approval, confirmation
• kutu = box
• kutu-su = box + its → a common way Turkish forms noun compounds

So this is not saying a box of approval in a natural English sense; it is simply the normal Turkish compound meaning checkbox.

Because Turkish often forms noun compounds with a special possessive ending on the second noun.

Here:

• onay = approval
• kutu = box
• onay kutusu = approval box / checkbox

That -su is the 3rd person possessive suffix, which is very commonly used in compound nouns.

Some similar examples:

• otobüs durağı = bus stop
• kimlik kartı = identity card
• telefon numarası = phone number

So onay kutusu is the normal compound form, not a full possessive phrase like the box of the approval.

görünmüyorsa can be broken down like this:

• görün- = appear / be visible
• -müyor = is not ...-ing / is not in that state
• -sa = if

So:

• görünüyor = it is visible / it is appearing
• görünmüyor = it is not visible
• görünmüyorsa = if it is not visible

This is a very common Turkish pattern:

• geliyorsa = if he/she/it is coming
• çalışmıyorsa = if it isn’t working
• açılmıyorsa = if it doesn’t open / if it isn’t opening

Because görünmek and görmek are different verbs.

• görmek = to see
• görünmek = to be seen / to appear / to be visible

So:

• görmezse would mean if he/she doesn’t see
• görünmezse would mean if it doesn’t appear / if it is not visible in a more general or habitual sense
• görünmüyorsa means if it isn’t visible in the current situation

In interface instructions, görünmüyorsa sounds very natural because it refers to what the user is seeing right now on the screen.

The ending -sa / -se means if.

Examples:

• gelirse = if he/she comes
• varsa = if there is
• istersen = if you want
• görünmüyorsa = if it is not visible

So in this sentence, the first part is a condition:

• Onay kutusu görünmüyorsa = If the checkbox is not visible

Then the second part gives the instruction:

• sayfayı biraz daha aşağı kaydır = scroll the page a little further down

Because it is the direct object of kaydır.

• sayfa = page
• sayfayı = the page

Turkish often uses the accusative ending -(y)ı / -(y)i / -(y)u / -(y)ü for a specific direct object.

Here:

• sayfa
  • -yı → sayfayı

The y is just a buffer consonant between two vowels.

So:

• sayfayı kaydır = scroll the page

This is similar to:

• kapıyı aç = open the door
• kitabı al = take the book
• ekranı kapat = turn off the screen

It means a little further down or a bit more downward.

Breakdown:

• biraz = a little
• daha = more / further
• aşağı = down / below

Together:

• biraz daha aşağı = a little more down / a little further down

This is very natural in Turkish for scrolling or moving lower on a page.

Examples:

• Biraz aşağı in. = Go down a little.
• Biraz daha bekle. = Wait a little longer.
• Biraz daha sağa kaydır. = Scroll/move a little more to the right.

Both can be possible in some contexts, but aşağı is very common and natural with movement words like kaydırmak.

• aşağı = down / downward
• aşağıya = to down / downward / to a lower place

In everyday Turkish, direction words are often used without the extra dative ending when the meaning is already clear:

• aşağı in = go down
• yukarı çık = go up
• sola dön = turn left
• biraz aşağı kaydır = scroll down a bit

So aşağı here is perfectly natural and idiomatic.

kaydır is the imperative form, used to give a command or instruction: scroll / move / slide.

The verb is kaydırmak, which means to slide, move, shift, scroll depending on context.

Here it means scroll.

So:

• kaydır = scroll / slide / move
• sayfayı aşağı kaydır = scroll the page down

This is the informal singular imperative, which is also the standard form used in instructions, manuals, and interface messages.

Grammatically, yes, it uses the plain imperative form, which matches you (singular informal). But in instructions, this form is also the normal neutral style.

So even though it looks like a command to you, it does not necessarily sound rude. It is just the standard concise way to give directions.

More polite versions are possible, for example:

• ... kaydırın = scroll ... (plural / polite)
• ... kaydırabilirsiniz = you can scroll ...
• ... kaydırmanız gerekiyor = you need to scroll ...

But for UI instructions, kaydır is very common and natural.

Because Turkish usually leaves out subject pronouns when they are understood from the verb form or the context.

In an instruction like this, the subject is obviously you.

So Turkish says:

• sayfayı ... kaydır = scroll the page ...

instead of explicitly saying:

• sen sayfayı ... kaydır

Adding sen would usually sound unnecessary unless you want emphasis.

This happens all the time in Turkish:

• Bekle. = Wait.
• Gel. = Come.
• Dikkat et. = Be careful.

The sentence follows a very typical Turkish pattern: condition first, main command last.

• Onay kutusu görünmüyorsa = If the checkbox is not visible
• sayfayı biraz daha aşağı kaydır = scroll the page a little further down

A more literal word-for-word order in English would be:

If the checkbox isn’t visible, the page a little more down scroll.

Turkish usually puts the main verb at the end, so kaydır comes last.

Yes, in natural English that can be a very good translation.

The Turkish literally focuses on the checkbox:

• Onay kutusu görünmüyorsa = If the checkbox is not visible

But in English, people often say:

• If you can’t see the checkbox, scroll down a little more.

That sounds natural, even though Turkish is not explicitly saying you can’t see. It is saying that the checkbox isn’t visible.

Historically and structurally, görünmek is related to the idea of being seen / appearing, but as a learner it is best to treat it as its own verb meaning:

• to appear
• to be visible
• to seem (in some contexts)

So in this sentence:

• görünmüyor = it is not visible / it doesn’t appear

You do not need to analyze it every time as a passive form of görmek. In practice, görünmek functions as a normal dictionary verb of its own.

This sentence contains a very common support/instruction pattern:

• X görünmüyorsa, Y yap. = If X isn’t visible, do Y.

Similar examples:

• Buton çalışmıyorsa sayfayı yenile.
  If the button isn’t working, refresh the page.

• Form açılmıyorsa tekrar dene.
  If the form doesn’t open, try again.

• Metin çok küçükse yakınlaştır.
  If the text is too small, zoom in.

• Menü görünmüyorsa yukarı kaydır.
  If the menu isn’t visible, scroll up.

This is a very useful structure to recognize in Turkish instructions.