Κάνω μια μικρή έρευνα πριν αγοράσω καινούριο λάπτοπ.

Greek often drops subject pronouns because the verb ending already tells you who is doing the action.

Here, κάνω already means I do / I am doing, so εγώ is not necessary.

• Κάνω... = I do...
• Εγώ κάνω... = I do... with extra emphasis, like I do...

So the sentence sounds natural without a separate word for I.

This is a very common Greek way to express the idea. Greek often uses κάνω + noun, just as English sometimes says do research.

• κάνω έρευνα = do research
• literally: do an investigation/research

There is also a verb ερευνώ (I investigate / I research), but κάνω έρευνα is very natural and everyday in this kind of sentence.

Here, μια is the feminine form of the indefinite article, so it means a.

• μια μικρή έρευνα = a little/small piece of research

It can also mean one in other contexts, depending on stress and meaning, but here it is just the ordinary a/an.

You may also see the spelling μία. Both are common.

μικρή is the feminine singular form of μικρός (small). It has to agree with έρευνα, which is a feminine singular noun.

So the pattern is:

• μικρός = masculine
• μικρή = feminine
• μικρό = neuter

Because έρευνα is feminine, Greek uses μικρή.

Also, in this sentence μικρή does not necessarily mean physically small. Very often it means something like a little, brief, or some.

It is the direct object of κάνω, so grammatically it is in the accusative. But many feminine nouns ending in -α look the same in the nominative and accusative singular.

So:

• nominative: η έρευνα
• accusative: την έρευνα

The noun itself stays έρευνα. What changes more clearly is the article, not the noun.

In your sentence there is no definite article, so you just see έρευνα.

αγοράσω is the aorist subjunctive form of αγοράζω (buy).

After πριν (before), Greek commonly uses the subjunctive for an action that has not happened yet. In English, you say before I buy; Greek uses πριν αγοράσω.

The aorist here does not mean past. It presents the action as a single whole event:

• αγοράσω = (that) I buy / before I buy
• αγόρασα = I bought → this is past

So αγοράσω is not past tense here.

After πριν, Greek very often uses the subjunctive without να:

• πριν αγοράσω

You may also hear:

• πριν να αγοράσω

Both exist in real Greek, and both are understandable. The version without να is very common and natural in a sentence like this.

So this is not a mistake; it is just a normal pattern after πριν.

Greek often leaves out the indefinite article when talking about something nonspecific or general, especially after verbs.

So:

• πριν αγοράσω καινούριο λάπτοπ = natural
• πριν αγοράσω ένα καινούριο λάπτοπ = also natural

The version without ένα sounds a bit more general: before buying a new laptop / before I buy a new laptop.

The version with ένα is a little more explicit. Both are possible.

καινούριο is the neuter singular form of καινούριος, agreeing with λάπτοπ, which is treated as neuter.

• masculine: καινούριος
• feminine: καινούρια
• neuter: καινούριο

Yes, you could also say νέο λάπτοπ.

The difference is roughly this:

• καινούριο often emphasizes brand-new / not used before
• νέο can simply mean new

In many everyday situations, both work.

You may also see καινούργιο. That is another common form/spelling.

λάπτοπ is a loanword from English, and in Greek it is usually treated as an indeclinable neuter noun. That means the noun itself often stays the same.

For example:

• το λάπτοπ = the laptop
• αγοράζω το λάπτοπ = I buy the laptop

The noun λάπτοπ stays λάπτοπ. The grammar is shown by the article and adjectives around it:

• καινούριο λάπτοπ
• το καινούριο λάπτοπ

Yes. Greek word order is more flexible than English word order.

Your sentence is perfectly natural:

• Κάνω μια μικρή έρευνα πριν αγοράσω καινούριο λάπτοπ.

But you could also say:

• Πριν αγοράσω καινούριο λάπτοπ, κάνω μια μικρή έρευνα.

Both mean the same basic thing. The difference is mostly about emphasis and flow:

• starting with Κάνω... focuses first on what you do
• starting with Πριν αγοράσω... focuses first on the time relation

So the original order is normal, but not the only possible one.