Πριν φύγω, τσεκάρω αν έχω το πορτοφόλι και τα κλειδιά μου.

Because after πριν meaning before, Greek normally uses the subjunctive for an action that has not happened yet.

So:

• πριν φύγω = before I leave

Here φύγω is the perfective form, which presents leaving as one whole event. That is exactly what Greek wants in this kind of sentence.

By contrast, φεύγω is the ordinary present/imperfective form, and it does not fit naturally here.

No. This is a very common point of confusion.

Even though φύγω is built from the same stem used for the aorist, here it is not past. In this sentence it is a subjunctive/perfective non-past form.

Compare:

• έφυγα = I left → actual past
• να φύγω / πριν φύγω = to leave / before I leave → not past

So φύγω here does not mean I left.

Yes. Πριν να φύγω is also possible and means the same thing.

Both of these are used:

• Πριν φύγω
• Πριν να φύγω

In everyday Greek, leaving out να after πριν is very common and natural.

Yes, it is real modern Greek, but it is informal and colloquial.

τσεκάρω comes from English check, and it means things like:

• I check
• I make sure
• I verify

So here τσεκάρω αν έχω... means I check whether I have...

A more formal or more traditionally Greek alternative could be:

• ελέγχω
• κοιτάζω
• βεβαιώνομαι ότι έχω...

But τσεκάρω is very common in everyday speech.

Here αν means whether or if in an indirect question.

So:

• τσεκάρω αν έχω το πορτοφόλι...
  = I check whether I have my wallet...

It is not really a condition here. It is introducing the thing being checked.

English often says either:

• I check if I have...
• I check whether I have...

Greek uses αν for that.

Because the speaker is checking a current state: whether they have the wallet and keys on them at that moment.

So Greek uses the present:

• αν έχω = whether I have / whether I’ve got

This is the natural way to say it. The idea is not whether I took them earlier, but whether I currently have them with me.

Greek uses the definite article much more often than English, especially with specific everyday objects and possessions.

So Greek normally says:

• το πορτοφόλι μου = my wallet
• τα κλειδιά μου = my keys

Even though English does not use the here, Greek usually does.

So the articles are completely normal and expected.

Because the weak possessive pronoun in Greek normally comes after the noun.

So:

• τα κλειδιά μου = my keys
• literally: the keys my

This is standard Greek word order.

The same word μου can mean:

• to me
• my

Its exact meaning depends on context. Here it is possessive, so it means my.

In context, many people will understand it as referring to both: my wallet and keys.

However, for a learner, it is useful to know that the clearest version is:

• το πορτοφόλι μου και τα κλειδιά μου

That removes any possible ambiguity.

So:

• το πορτοφόλι και τα κλειδιά μου = often understood as my wallet and keys
• το πορτοφόλι μου και τα κλειδιά μου = fully explicit and safest

Native speakers often rely on context, but repeating μου is clearer.

Most naturally, it sounds habitual or general:

• Before I leave, I check whether I have my wallet and keys.

That is, it describes something the speaker normally does.

Greek present tense is often used this way for routines and habits. In the right context, it could also refer to a specific situation, but without extra context the habitual reading is the most natural.

Here is a quick breakdown:

• φύγω = I leave in the subjunctive/perfective form, used after πριν
• τσεκάρω = I check, 1st person singular present
• έχω = I have, 1st person singular present

So all three verbs refer to I, but they are used in different grammatical environments:

• πριν φύγω = subordinate clause after πριν
• τσεκάρω = main verb of the sentence
• αν έχω = indirect question introduced by αν