Βάζω τον σπόρο στη γλάστρα και μετά ρίχνω λίγο νερό.

Because Greek often leaves out the subject pronoun when it is already clear from the verb ending.

• βάζω = I put / I am putting
• ρίχνω = I pour / I am pouring

So Greek does not need εγώ unless you want emphasis, contrast, or clarity.

• Βάζω τον σπόρο... = I put the seed...
• Εγώ βάζω τον σπόρο... = I’m the one putting the seed... or I put the seed... with emphasis

They are in the present tense.

In Greek, the present can be used in a few ways:

• for something happening now
• for habitual actions
• for instructions or step-by-step description

So here it sounds very natural for describing a process:

• Βάζω τον σπόρο... και μετά ρίχνω...
• I put the seed... and then I pour...

In English, depending on context, this could sound like:

• I put the seed in the pot and then pour a little water
• I’m putting the seed in the pot and then pouring a little water
• First I put the seed in the pot, then I pour a little water

Because τον σπόρο is the direct object, so it is in the accusative case.

The dictionary form is ο σπόρος = the seed
But after a verb like βάζω when the noun is the thing being acted on, Greek uses the accusative:

• ο σπόρος = the seed subject form
• τον σπόρο = the seed object form

So:

• Ο σπόρος είναι μικρός. = The seed is small.
• Βάζω τον σπόρο στη γλάστρα. = I put the seed in the pot.

Because Greek has grammatical gender, not just biological gender.

That means every noun belongs to a grammatical category such as:

• masculine
• feminine
• neuter

So:

• ο σπόρος is masculine
• η γλάστρα is feminine
• το νερό is neuter

This does not mean the objects themselves have natural gender. It just affects:

• the article
• adjectives
• some pronoun forms

English speakers often need time to get used to this, because English mostly does not mark grammatical gender on nouns.

στη is a contraction of σε + τη(ν).

• σε = in, at, to, into
• τη(ν) = the feminine singular article in the accusative

So:

• στη γλάστρα = in / into the pot

This contraction is very common in Greek:

• στο = σε + το
• στον = σε + τον
• στη = σε + τη(ν)

It can mean either, depending on context.

Modern Greek often uses σε for both:

• location: in / at
• movement toward something: to / into

So in this sentence, because the action is putting the seed, English naturally translates it as into the pot, even though Greek says στη γλάστρα.

Compare:

• Το λουλούδι είναι στη γλάστρα. = The flower is in the pot.
• Βάζω τον σπόρο στη γλάστρα. = I put the seed into the pot.

Because Greek often leaves out the article when talking about an indefinite amount of a mass noun.

• νερό = water
• λίγο νερό = a little water / some water

This is very natural. If you added the article, it would usually change the meaning:

• λίγο νερό = a little water
• το λίγο νερό = the little water / the small amount of water

Also, λίγο here is the neuter singular form, matching νερό, which is neuter:

• λίγος for masculine
• λίγη for feminine
• λίγο for neuter

Because the two verbs have different natural uses.

• βάζω means put, place
• ρίχνω means throw, drop, pour depending on context

With a seed, you are placing it somewhere, so βάζω is natural.

With water, Greek often uses ρίχνω in the sense of pour or add liquid.

So:

• Βάζω τον σπόρο... = I put the seed...
• ρίχνω λίγο νερό = I pour a little water / add a little water

You could also hear other verbs in gardening contexts, such as ποτίζω = water a plant, but that would not mean exactly the same thing as ρίχνω λίγο νερό in this sentence.

Here μετά means then or afterwards.

It connects the steps in a sequence:

• Βάζω τον σπόρο στη γλάστρα και μετά ρίχνω λίγο νερό.
• I put the seed in the pot and then I pour a little water.

Be careful: μετά can also mean after in other structures, often with από.

For example:

• μετά από μία ώρα = after one hour

But in your sentence, it is simply an adverb meaning then.

Yes. Greek word order is more flexible than English because case endings and verb forms carry a lot of information.

The sentence as given is very natural and neutral:

• Βάζω τον σπόρο στη γλάστρα και μετά ρίχνω λίγο νερό.

But Greek can move things around for emphasis:

• Μετά ρίχνω λίγο νερό. = Then I pour a little water.
• Τον σπόρο βάζω στη γλάστρα... = emphasis on the seed
• Λίγο νερό ρίχνω μετά. = emphasis on a little water

Not every possible order sounds equally natural in every situation, but Greek is definitely less rigid than English.

It is also in the accusative.

After the preposition σε, Modern Greek uses the accusative:

• η γλάστρα = nominative
• τη(ν) γλάστρα = accusative
• στη γλάστρα = σε + τη(ν) γλάστρα

So both important noun phrases in the sentence are accusative:

• τον σπόρο because it is the direct object
• στη γλάστρα because it follows σε

A rough pronunciation guide is:

VA-zo ton SPO-ro sti GLA-stra ke me-TA REE-khno LEE-go ne-RO

A few notes:

• βάζω: stress on βά
• σπόρο: stress on σπό
• γλάστρα: stress on γλά
• μετά: stress on the second syllable
• ρίχνω: the χ is not like English k or h; it is a rough sound, like German Bach or Scottish loch
• νερό: stress on the last syllable

Greek stress matters, so the accent marks help show where the voice should fall.