Post la tagmanĝo mi devas purigi la plankon en la kuirejo.

Post is a preposition, and one of its common meanings is after.

So:

• post la tagmanĝo = after lunch / after the lunch meal

In Esperanto, prepositions like post, en, sur, kun, and por usually introduce a phrase and show the relationship between words.

Examples:

• post la laboro = after work
• post la leciono = after the lesson
• post la tagmanĝo = after lunch

Tagmanĝo is a compound word:

• tago = day
• manĝo = meal, eating

So tagmanĝo literally means day-meal, which is the usual Esperanto word for lunch.

Related words:

• matenmanĝo = breakfast
• tagmanĝo = lunch
• vespermanĝo = dinner / evening meal

This kind of word-building is very common in Esperanto.

La is the definite article, meaning the.

In this sentence, post la tagmanĝo can be understood as after the lunch meal, meaning the specific lunch being talked about in this situation.

In practice, Esperanto sometimes uses la in places where English might simply say after lunch without an article. You may also hear post tagmanĝo in some contexts, but post la tagmanĝo is completely normal and natural.

So the article is not strange here—it helps make the meal feel definite and concrete.

There are two verb forms because devas expresses necessity, and purigi is the actual action.

• mi devas = I must / I have to
• purigi = to clean

Together:

• mi devas purigi = I have to clean

This works much like English:

• I must go
• I have to study
• I have to clean

In Esperanto, after devas, the next verb stays in the infinitive form, which ends in -i.

More examples:

• Mi devas labori. = I have to work.
• Ŝi devas iri hejmen. = She has to go home.

Devas comes from devi, meaning to have to, to be obliged to, or must.

So:

• mi devas purigi can mean
  
  • I must clean
  • I have to clean
  • I need to clean

The exact English translation depends on context. In many everyday sentences, must and have to are both reasonable translations.

Purigi means to clean something.

It is built from:

• pura = clean
• -ig- = make, cause to become

So purigi literally means to make clean.

That is why it works with a direct object:

• purigi la plankon = to clean the floor

This is a very important Esperanto pattern:

• varma = warm

• varmigi = to warm something up, make something warm

• seka = dry

• sekigi = to dry something

• pura = clean
• purigi = to clean something

The -n ending marks the direct object.

Here, the thing being cleaned is the floor, so la plankon is the direct object of purigi.

• la planko = the floor
• purigi la plankon = to clean the floor

This is one of the most important uses of -n in Esperanto.

Compare:

• La planko estas malpura. = The floor is dirty.

  • la planko is the subject, so no -n

• Mi purigas la plankon. = I am cleaning the floor.

  • la plankon is the object, so it takes -n

Because this phrase shows location, not movement toward a place.

• en la kuirejo = in the kitchen
• en la kuirejon = into the kitchen

In the sentence, the floor is located in the kitchen. Nobody is moving into the kitchen in this phrase. So the ordinary location form is used:

• en la kuirejo = in the kitchen

Compare:

• Mi estas en la kuirejo. = I am in the kitchen.
• Mi iras en la kuirejon. = I am going into the kitchen.

It most naturally tells you which floor is meant: the floor in the kitchen.

So the idea is:

• la plankon en la kuirejo = the floor in the kitchen

Of course, it also relates to the action, because that is the floor being cleaned. But in meaning, it most directly identifies the noun planko.

English works similarly:

• I have to clean the floor in the kitchen.

Usually that means the kitchen floor, not that the act of cleaning happens while you are somehow located in the kitchen cleaning some other floor.

Yes, the word order could be different.

Esperanto word order is fairly flexible, because grammatical endings make the roles of words clear. The version in the sentence puts the time expression first:

• Post la tagmanĝo mi devas purigi la plankon en la kuirejo.

This emphasizes when the action happens.

You could also say:

• Mi devas purigi la plankon en la kuirejo post la tagmanĝo.

That is also correct. It just feels slightly different in focus.

Putting post la tagmanĝo first is very natural if you want to start with the time setting.

Normally, Esperanto does not leave out the subject pronoun.

So you usually say:

• mi devas = I have to
• vi devas = you have to
• li devas = he has to

Even though devas has a clear verb ending, it does not tell you the person by itself. The form devas is the same with mi, vi, li, ŝi, ni, ili, etc.

That is why the pronoun is needed:

• Mi devas purigi... = I have to clean...

In this sentence, planko means floor.

That is the normal meaning of planko in everyday use.

A single wooden plank would usually be:

• tabulo = board, plank

So:

• la planko = the floor
• tabulo = a board / plank

Because the sentence is about cleaning something in a kitchen, planko clearly means floor.

Yes, many speakers would understand lunĉo, since it is a borrowed word and is used by some people. But tagmanĝo is a very standard, clearly Esperanto-style word.

So:

• tagmanĝo = very common and fully regular Esperanto
• lunĉo = also understandable, but less characteristically Esperanto

Learners are often encouraged to get comfortable with words like tagmanĝo, because Esperanto often prefers transparent compounds built from familiar roots.

Here are the main words and their dictionary forms:

• post = after
• la = the
• tagmanĝo = lunch
• mi = I
• devas → devi = to have to, must
• purigi = to clean
• la = the
• plankon → planko = floor
• en = in
• la = the
• kuirejo = kitchen

And here are the important endings:

• -o = noun
• -on = noun + direct object
• -as = present tense verb
• -i = infinitive verb

So for example:

• devas = present tense of devi
• plankon = planko with the object ending -n

A simple breakdown is:

• Post la tagmanĝo = time phrase
• mi = subject
• devas purigi = verb phrase
• la plankon = direct object
• en la kuirejo = location phrase describing the floor

So the sentence structure is basically:

After lunch + I + have to clean + the floor + in the kitchen

This is a very typical Esperanto sentence pattern and a good example of how clear endings make the grammar easy to follow.