Ni trinkas akvon ĉe la fonto.

The ending -as marks the present tense in Esperanto.

So trinki = to drink, and trinkas = drink / are drinking.

In Esperanto, the verb ending already shows the tense, so you do not need an extra word like do, is, or are.
That means Ni trinkas can mean:

• We drink
• We are drinking

The exact meaning depends on context.

The -n ending marks the direct object. That is the thing directly affected by the verb.

In this sentence:

• Ni = the subject, the ones doing the action
• trinkas = the action
• akvon = the thing being drunk

So akvo means water, but akvon means water as the direct object.

This is called the accusative ending.

Esperanto does not require an article in as many places as English does.

So akvon can simply mean:

• water
• some water

If you said la akvon, that would mean the water, referring to specific water already known from the context.

In this sentence, the speaker is just talking about drinking water, not necessarily a particular already-identified water.

Ĉe usually means at, by, or near.

So ĉe la fonto means something like:

• at the fountain
• by the spring
• near the source

It gives the location of the action.

A useful way to think about ĉe is that it often means being in the vicinity of something, not necessarily inside it or on top of it.

La is the definite article, meaning the.

So:

• fonto = a fountain / a spring
• la fonto = the fountain / the spring

Here, la suggests that the speaker has a particular fountain or spring in mind, or that it is identifiable from the context.

Unlike English, Esperanto uses just one definite article: la. It does not change for gender, number, or case, though if there were an adjective with an accusative ending, the adjective would change, not la.

It can mean either, depending on context.

Most basically, fonto means a source from which water comes out. So it may refer to:

• a spring
• a fountain
• sometimes more generally a source

If the meaning has already been given to the learner, then that specific translation is probably the intended one in this sentence. But yes, English speakers often notice that fonto can cover more than one related idea.

Yes, Esperanto word order is fairly flexible, because endings help show what each word is doing.

For example, these would still be understandable:

• Ni trinkas akvon ĉe la fonto.
• Ĉe la fonto ni trinkas akvon.
• Akvon ni trinkas ĉe la fonto.

Because akvon has the -n ending, you can still tell it is the object.

That said, the most neutral word order is usually subject + verb + object, as in the original sentence.

It can mean both.

Esperanto does not usually make a separate grammatical distinction between:

• we drink
• we are drinking

Both can be expressed as ni trinkas.

If you need to make the meaning clearer, you usually do it through context or extra words, not by changing the basic present-tense ending.

Ĉ is pronounced like ch in church.

So ĉe sounds roughly like cheh.

A simple pronunciation guide:

• ĉ = ch
• e = a short pure vowel, like e in bet but without turning it into a diphthong

So ĉe is approximately cheh.

A rough guide:

• fonto ≈ FOHN-to
• akvon ≈ AHK-von

A few details:

• Esperanto stress normally falls on the second-to-last syllable
• so FON-to is stressed on FON
• and AK-von is stressed on AK

Also, Esperanto vowels are pronounced clearly and consistently:

• a = ah
• o = oh

Because Esperanto main verbs already carry tense by their endings.

So trinkas already means drink / are drinking, and that is enough.

You would not normally say Ni estas trinkas. That is incorrect.

If you want the idea we are plus a description, then estas is used with nouns, adjectives, or certain participle constructions. But for a simple present-tense action, just use the verb itself:

• Ni trinkas = We drink / We are drinking

Yes.

In Esperanto, adjectives agree with the nouns they describe in both number and case.

So if you had an adjective with akvon, it would also take -n:

• Ni trinkas malvarman akvon. = We drink cold water.

Here:

• malvarma akvo = cold water
• malvarman akvon = direct object, so both words take -n

This is a very common pattern in Esperanto.