Перед отправкой я заполняю анкету и ставлю галочку.

Because перед normally takes the instrumental case.

• отправка = sending / submission
• instrumental singular of отправка is отправкой

So:

• перед отправкой = before sending / before submission

This is true whether перед means:

• in front of something, or
• before something in time

Examples:

• перед домом = in front of the house
• перед встречей = before the meeting
• перед отправкой = before sending

Here отправка means sending or submitting something.

In context, it probably means something like:

• sending a form
• submitting an application
• sending a message
• submitting data online

Russian often leaves the object unstated if it is obvious from context. So перед отправкой can sound natural even if it does not say exactly what is being sent.

They are in the present tense imperfective, which often describes:

• a habitual action
• a usual procedure
• a general rule
• what someone does as part of a process

So this sentence sounds like:

• Before submitting, I fill out the form and tick the box
• in the sense of that’s what I do / that’s the step in the process

It does not necessarily mean the speaker is doing it right this second. Russian present tense is often used this way for routine actions.

This is a question of aspect.

• заполняю = imperfective
• заполню = perfective
• ставлю = imperfective
• поставлю = perfective

In this sentence:

• заполняю
• ставлю

suggest an ongoing, habitual, or standard action.

If you wanted to talk about one specific future completed action, you would more likely say:

• Перед отправкой я заполню анкету и поставлю галочку.

That means something like:

• Before submitting, I’ll fill out the form and tick the box.

So:

• imperfective = process, habit, repeated action
• perfective = completed result, one whole action

Because they are the direct objects of the verbs.

• заполняю что? → анкету
• ставлю что? → галочку

Both nouns are feminine, and in the singular their accusative forms look like this:

• анкета → анкету
• галочка → галочку

So this is a very common pattern:

• feminine noun ending in -а usually becomes -у in the accusative singular

Yes and no.

Literally, галочка means a little check mark / tick mark. But the phrase ставить галочку is also a very common expression meaning:

• to tick a box
• to check a checkbox
• to mark something with a tick

So in forms, websites, and documents, ставить галочку is extremely natural.

A learner should know that галочка is a diminutive form, but in this expression it sounds completely normal and standard. It does not feel especially childish here.

It can mean either, depending on context.

Common translations include:

• questionnaire
• form
• application form
• profile form

In many real-life situations, анкета is a form with personal information or questions to fill in. So translating it as form is often very natural.

Yes. Russian word order is flexible.

The original sentence:

• Перед отправкой я заполняю анкету и ставлю галочку.

puts перед отправкой first, which emphasizes the time frame: before submitting.

You could also say:

• Я перед отправкой заполняю анкету и ставлю галочку.

This is also grammatical, but it shifts the focus slightly more onto I.

If you move перед отправкой to the end:

• Я заполняю анкету и ставлю галочку перед отправкой.

that is still understandable, but the original version usually sounds smoother if you want to frame the whole action as happening before submission.

Very possibly, yes.

Russian often omits words that are clear from context. So перед отправкой may really mean:

• before sending the form
• before submitting the application
• before sending the message
• before submitting everything

If you wanted to be more explicit, you could say things like:

• Перед отправкой анкеты... = Before sending the form...
• Перед отправкой заявки... = Before submitting the application...

But if everyone already knows what is being sent, the shorter перед отправкой is normal.

Yes, absolutely.

You could say:

• Перед тем как отправить, я заполняю анкету и ставлю галочку.

or more explicitly:

• Перед тем как отправить анкету, я ставлю галочку.

This structure means before doing X and is very common in Russian.

The difference is mostly stylistic:

• перед отправкой = more compact, noun-based
• перед тем как отправить = more verbal, more explicit

Both are correct.

Then Russian would usually prefer the perfective future:

• Перед отправкой я заполню анкету и поставлю галочку.

This means:

• Before submitting, I’ll fill out the form and tick the box.

So compare:

• заполняю / ставлю = what I generally do, or what happens as part of the procedure
• заполню / поставлю = what I will do this one time, as a completed action

That aspect difference is one of the most important things to notice in this sentence.