Kiam ni estas en la granda urbo, ni vidas stelojn preskaŭ nenie, sed mia filino tamen serĉas ilin ĉe la fenestro.

Kiam means when and introduces a time clause.
So Kiam ni estas en la granda urbo means When we are in the big city.

In Esperanto, a clause beginning with kiam works much like English when:

• Kiam pluvas, ni restas hejme. = When it rains, we stay home.

Esperanto usually keeps the verb esti (to be) where English would also use are/is/am. So:

• ni estas en la granda urbo = we are in the big city

You normally do not drop estas there.

• en = in
• la = the
• granda = big
• urbo = city

So en la granda urbo literally means in the big city.

The adjective granda ends in -a because it describes a noun, and it matches urbo in form.

La is the definite article, meaning the. Esperanto has only one article: la. It does not change for gender, number, or case.

So:

• la urbo = the city
• la granda urbo = the big city

Because stelojn is the direct object of vidas (see).

In Esperanto:

• -j marks plural
• -n marks the accusative, usually the direct object

So:

• stelo = star
• steloj = stars
• stelojn = stars, as the thing being seen

Since ni vidas stelojn means we see stars, the noun gets -n.

For the same reason: ilin is also a direct object.

• ili = they
• ilin = them

In mia filino tamen serĉas ilin, the daughter is searching for them, so the pronoun takes the accusative -n.

• preskaŭ = almost
• nenie = nowhere

Together, preskaŭ nenie means almost nowhere.

So ni vidas stelojn preskaŭ nenie means that in the big city, stars are visible in hardly any place at all.

Esperanto has a regular system of correlatives, and nenie is the standard word meaning nowhere.

Some related forms are:

• ie = somewhere
• ĉie = everywhere
• nenie = nowhere
• kie = where

Using nenie is natural and standard Esperanto.

Tamen means however, nevertheless, or still.

In this sentence, it shows contrast:

• We can hardly see stars in the city,
• but the daughter still / nevertheless looks for them.

So tamen adds the idea of persistence despite the situation.

Esperanto word order is fairly flexible, and tamen can often move around depending on emphasis.

For example, these are all possible with slightly different emphasis:

• Mia filino tamen serĉas ilin...
• Tamen mia filino serĉas ilin...
• Mia filino serĉas ilin tamen...

The version in your sentence sounds natural and places the contrast nicely after the subject.

It can correspond to both, depending on context.

• serĉi ion = to look for something
• serĉi iun = to search for someone

So mia filino tamen serĉas ilin means my daughter still looks for them or keeps searching for them.

Ĉe usually means at, by, or near.

So ĉe la fenestro suggests that she is at the window or by the window.

Compare:

• ĉe la fenestro = at/by the window
• en la fenestro = in the window
• tra la fenestro = through the window

Here, ĉe la fenestro is the natural choice if she is standing or sitting by the window while looking out.

Yes, but it would mean something slightly different.

• ĉe la fenestro focuses on her position: she is at the window
• tra la fenestro focuses on the direction of looking: she is looking through the window

If the idea is mainly where she is, ĉe la fenestro is good. If you wanted to emphasize that she is looking outward through the glass, tra la fenestro could also make sense in a different sentence.

Esperanto often uses the present tense for general or repeated situations, just as English does.

So:

• Kiam ni estas en la granda urbo = When we are in the big city
• ni vidas... = we see...
• mia filino serĉas... = my daughter looks for...

This does not have to mean only one specific moment. It can describe a usual pattern.

Because the sentence has two main clauses:

1. Kiam ni estas en la granda urbo
2. ni vidas stelojn preskaŭ nenie

The second clause needs its own subject, so ni is stated again. Esperanto normally expresses the subject clearly rather than leaving it understood from the previous clause.

Esperanto endings give a lot of grammatical information:

• -as = present tense verb
  
  • estas, vidas, serĉas
• -o = noun
  
  • urbo
• -a = adjective
  
  • granda
• -j = plural
  
  • steloj
• -n = accusative/direct object
  
  • stelojn, ilin

Because of these endings, you can often tell what each word is doing even before translating everything word-for-word.