Я прикріплю файл.

I

Breakdown of Я прикріплю файл.

• файл: the file
• прикріпити: to attach a file

Questions & Answers about Я прикріплю файл.

Why is the verb прикріплю used here, and what tense is it?

прикріплю is the 1st person singular future form of the verb прикріпити (to attach).

So:

• я прикріплю = I will attach

This is a perfective verb, so its future form usually means a single completed action: attaching the file once.

A useful comparison:

• Я прикріплю файл. = I will attach the file.
• Я прикріпляю файл. = I am attaching the file / I attach the file.

So this sentence sounds natural when someone is about to attach a file, for example in email or chat.

Why is я included? Can Ukrainian leave it out?

Yes, Ukrainian often drops subject pronouns when they are clear from the verb ending.

So both of these are possible:

• Я прикріплю файл.
• Прикріплю файл.

Because прикріплю already tells you the subject is I, я is not always necessary.

Including я can add:

• emphasis
• clarity
• contrast

For example:

• Я прикріплю файл, а ти надішлеш листа.
  I will attach the file, and you will send the email.

So in this sentence, я is correct, but it is not always required.