Malgraŭ la vento la tendo restis apud la fonto.

Malgraŭ means despite / in spite of. It is a preposition, so it introduces a noun phrase:

• malgraŭ la vento = despite the wind

A useful thing to notice is that Esperanto prepositions are very regular. You do not have to change malgraŭ depending on number, gender, or case in the way you might in some other languages.

La is the Esperanto definite article, equivalent to the. It does not change form.

In this sentence:

• la vento = the wind
• la tendo = the tent
• la fonto = the spring / fountain

Esperanto uses la whenever the speaker has a specific thing in mind. English learners sometimes feel it is repeated a lot, but that is normal.

Because -o is the standard noun ending in Esperanto.

So:

• vento = wind
• tendo = tent
• fonto = spring, source, fountain

This is one of the most helpful features of Esperanto: word classes are very easy to spot.

• -o = noun
• -a = adjective
• -e = adverb
• -i = infinitive verb

Because -is marks the past tense.

So:

• restas = stays / remains
• restis = stayed / remained

The verb root is rest-, meaning stay or remain. The ending tells you the tense:

• -as = present
• -is = past
• -os = future

Resti usually means to remain, to stay, or to keep being in a place/state.

In this sentence, it means that the tent continued to be by the spring; it did not get blown away or moved elsewhere.

So restis apud la fonto is something like:

• remained by the spring
• stayed beside the spring

Apud means beside, next to, or by the side of. It suggests physical nearness.

• apud la fonto = beside the spring

It is similar to ĉe, but not exactly the same:

• apud = beside, next to
• ĉe = at, by, in the vicinity of

So apud is usually a bit more specifically spatial.

Because there is no direct object here, and the sentence describes location, not movement toward something.

Important points:

• la tendo is the subject, so no -n
• apud la fonto shows location, so no -n
• malgraŭ la vento is a prepositional phrase, so normally no -n

You might see -n after a preposition when it shows direction:

• apud la fonto = beside the spring
• apud la fonton = to a position beside the spring

But in your sentence, the tent is already there, so no accusative is needed.

Esperanto word order is fairly flexible, although some orders sound more natural than others.

This sentence is perfectly normal:

• Malgraŭ la vento la tendo restis apud la fonto.

You could also say:

• La tendo restis apud la fonto malgraŭ la vento.

That would still be understandable. The version with malgraŭ la vento first gives a little more emphasis to the contrast: despite the wind...

So the first phrase is being foregrounded, much like in English.

Usually, no comma is necessary.

• Malgraŭ la vento la tendo restis apud la fonto.

That is a normal, clean sentence. A comma could sometimes appear for style or emphasis, especially in longer sentences, but it is not required here.

Esperanto punctuation is generally fairly straightforward and often follows clarity rather than very strict comma rules for short prepositional phrases.

A simple guide:

• mal-graŭ

The aŭ is a diphthong, roughly like ow in cow, though often shorter and cleaner.

Very approximate English-style pronunciation:

• mal-GROW? Not quite.
• Better: mal-GRAU, with au like in cow

Also:

• g is always a hard g
• r is usually rolled or tapped
• stress in Esperanto falls on the second-to-last syllable

So malGRAŬ has the stress on graŭ.

Esperanto uses the singular if the idea is just wind as a force or the wind in that situation.

• la vento = the wind

If you wanted actual multiple winds in some special sense, you could say la ventoj, but that would be unusual here. Just as in English, the wind is the natural choice for ordinary weather.

Yes, fonto can mean spring, source, or sometimes fountain, depending on context.

Esperanto roots are often a little broader than single English words. The surrounding context tells you what is meant.

For example:

• in nature: probably spring
• in a town square: probably fountain
• figuratively: possibly source

So the exact English translation depends on the situation, not just the word by itself.