Başvuru dilekçesi eksik; dolayısıyla elektronik başvuru geçerli değil.

The application petition is incomplete; therefore, the electronic application is not valid.

Breakdown of Başvuru dilekçesi eksik; dolayısıyla elektronik başvuru geçerli değil.

• değil: not
• eksik: incomplete
• geçerli: valid
• başvuru dilekçesi: an application petition

Questions & Answers about Başvuru dilekçesi eksik; dolayısıyla elektronik başvuru geçerli değil.

Why is it başvuru dilekçesi and not something like başvuru dilekçe?

This is a very common Turkish pattern called an indefinite noun compound.

• başvuru = application
• dilekçe = petition / formal written request
• dilekçesi = dilekçe
  • the compound ending -si

So başvuru dilekçesi means application petition / application letter.

In this structure:

• the first noun stays plain: başvuru
• the second noun takes a possessive-type ending: dilekçesi

You see the same pattern in phrases like:

• öğrenci kartı = student card
• kimlik numarası = identity number
• başvuru formu = application form

So başvuru dilekçesi is the normal Turkish way to say this kind of compound noun.

Does the -si in dilekçesi mean his/her?

Not here.

Although -si / -sı / -su / -sü can be a third-person possessive suffix, in a phrase like başvuru dilekçesi it is functioning as part of the noun-compound structure, not necessarily meaning his/her petition.

So in this sentence:

• başvuru dilekçesi = application petition

not

• his/her application petition

English does not really show this structure directly, so it can feel strange at first. A good way to think of it is: Turkish often marks the second noun in a noun-noun combination.