En novembro kaj decembro mi preferas varman teon, sed en julio kaj aŭgusto mi trinkas pli da akvo.

Here, en means in or during when talking about months and time periods.

• en novembro = in November
• en julio kaj aŭgusto = in July and August

This is the normal way to say that something happens during those months.

Because in Esperanto, all nouns normally end in -o. Month names are nouns, so they follow the same rule:

• novembro
• decembro
• julio
• aŭgusto

This is completely regular Esperanto grammar.

In Esperanto, names of months and days are usually written with lowercase letters, not capitals.

So Esperanto writes:

• novembro
• decembro
• julio
• aŭgusto

This is different from English, where November and July are capitalized.

The ending -as shows the present tense in Esperanto.

So:

• preferas = prefers / prefer
• trinkas = drinks / drink

Esperanto verb endings are very regular:

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

So mi preferas means I prefer.

Because varman teon is the direct object of preferas.

In Esperanto, a direct object usually takes -n. Also, any adjective describing that noun must match it.

Base form:

• varma teo = warm tea

In the sentence:

• varman teon

Why?

• teo → teon because it is the direct object
• varma → varman because the adjective must agree with teon

So both words change.

Yes. In Esperanto, adjectives agree with the nouns they describe in both:

• number
• case

Examples:

• varma teo = warm tea
• varmaj teoj = warm teas
• varman teon = warm tea as a direct object
• varmajn teojn = warm teas as direct objects

So varman teon is a normal example of adjective agreement.

Esperanto has:

• no indefinite article like English a/an
• a definite article la

But la is only used when something is specific.

In this sentence, the speaker is talking generally about what they prefer to drink, not about one specific tea or one specific water. So no article is needed.

That is very natural in Esperanto.

Sed means but.

It connects two contrasting ideas:

• in some months, the speaker prefers warm tea
• in other months, the speaker drinks more water

So sed works exactly like English but in this sentence.

Pli da akvo literally means more of water, but in natural English we simply say more water.

Esperanto uses da after words of quantity or amount, such as:

• pli da = more
• multe da = a lot of
• iom da = some
• sufiĉe da = enough

So:

• pli da akvo = more water

You use da because akvo is being measured as an amount.

Because after da, the noun usually stays in its basic form.

So we say:

• pli da akvo not
• pli da akvon

The whole expression pli da akvo functions as the object of trinkas, but the noun after da itself does not take the accusative ending.

This is a very common pattern in Esperanto.

Not with exactly the same meaning.

• pli da akvo = a greater quantity of water
• plia akvo = additional water, extra water

So pli da akvo focuses on amount. Plia akvo sounds more like some extra water or another amount of water.

In this sentence, pli da akvo is the more natural choice.

Because teo and akvo are usually treated as mass nouns, like in English.

You normally say:

• teo = tea
• akvo = water

not plurals, unless you mean different kinds or servings.

So varman teon means warm tea in a general sense, not one single tea leaf or one counted tea.

In aŭgusto, the aŭ is pronounced like the ow in cow.

So aŭgusto is approximately:

• ow-GUS-to

Also, Esperanto stress normally falls on the second-to-last syllable, so the stress is on GUS.

That same stress rule works for most Esperanto words, which makes pronunciation very predictable.