Di giorno lavoro in ufficio, ma la sera leggo in giardino.

These are both common time expressions, but they are built differently:

• di giorno = during the day / by day
• la sera = in the evening

Italian often uses:

• di + noun for general time periods:
  
  • di giorno = in the daytime
  • di notte = at night

But it also often uses the definite article with parts of the day:

• la mattina = in the morning
• il pomeriggio = in the afternoon
• la sera = in the evening

So this is not a strict rule you can always predict from English; it is largely a matter of common Italian usage.

Yes, di sera exists and means in the evening / in the evenings, but it can sound a little different from la sera depending on context.

Very roughly:

• la sera often refers to a habitual time slot: in the evening
• di sera can sound a bit more like in the evenings / at evening time, sometimes slightly more literary or stylistically marked depending on the sentence

In many everyday contexts, both are possible, but la sera is extremely common and natural here.

Because Italian usually drops subject pronouns when they are not needed.

• lavoro already means I work
• leggo already means I read

The verb ending tells you the subject:

• -o = I

So:

• (io) lavoro
• (io) leggo

The pronoun io is normally omitted unless you want emphasis, contrast, or clarity.

They are both in the present indicative.

• lavoro = I work / I am working
• leggo = I read / I am reading

In a sentence like this, the present tense is often used for habitual actions:

• Di giorno lavoro in ufficio = During the day I work in an office / at the office
• la sera leggo in giardino = In the evening I read in the garden

Italian uses the simple present much like English uses both I work and sometimes I am working, depending on context.

Because in is the normal preposition here for being or doing something in a place / inside a place.

• in ufficio = in the office / at the office
• in giardino = in the garden

Italian prepositions do not always match English exactly, so it is best to learn common combinations:

• in ufficio
• in casa
• in giardino
• in cucina

By contrast, a is used in other place expressions, for example:

• a casa = at home
• a scuola = at school
• al mare = at the seaside

Italian often omits the article after a preposition when referring to a place in a general, everyday sense.

So:

• in ufficio = at work / in the office
• in giardino = in the garden

If you say:

• nell’ufficio
• nel giardino

that usually sounds more specific, as if you mean a particular office or a particular garden already identified in the conversation.

Compare:

• Lavoro in ufficio. = I work in an office / at the office (general)
• Lavoro nell’ufficio di mio padre. = I work in my father’s office (specific)

Ma means but.

It connects the two parts of the sentence and shows contrast:

• Di giorno lavoro in ufficio = During the day I work in the office
• ma la sera leggo in giardino = but in the evening I read in the garden

The contrast is between the two time periods and activities.

Yes, that is perfectly possible.

Italian word order is somewhat flexible, especially with time expressions like:

• di giorno
• la sera

The original sentence is natural, but you can move those elements for emphasis or style:

• Di giorno lavoro in ufficio, ma la sera leggo in giardino.
• La sera leggo in giardino, ma di giorno lavoro in ufficio.

Both are correct. The first version emphasizes the daytime activity first; the second starts with the evening routine.

Because it comes from the verb leggere = to read.

Its present tense is:

• io leggo
• tu leggi
• lui/lei legge
• noi leggiamo
• voi leggete
• loro leggono

The double gg is part of the verb stem in these forms. It is not something added just for this sentence.

Also note that leggo is pronounced roughly like LEH-ggo, with a hard g sound.

It can mean either, depending on context.

Italian in ufficio often corresponds to natural English:

• in the office
• at the office
• sometimes even at work

So you should not expect a perfect one-to-one match with English prepositions.

Most naturally, it describes a routine or habit.

• Di giorno lavoro in ufficio, ma la sera leggo in giardino. = During the day I work in the office, but in the evening I read in the garden.

Because of the time expressions di giorno and la sera, the sentence strongly suggests a repeated pattern in daily life.

Without more context, it is not usually understood as only what is happening at this exact moment.

Yes. Lavorare in ufficio is the common, natural expression for working in an office / at the office.

All’ufficio can exist, but it usually means something more like at the office in a more location-focused or specific sense, and it is less natural as the default expression here.

For a learner, the safest choice is:

• lavorare in ufficio

Because Italian often expresses that idea more simply.

Instead of translating word-for-word, Italian commonly uses set expressions like:

• di giorno = during the day / by day
• la sera = in the evening
• di notte = at night

So the sentence sounds natural in Italian even though it is not built exactly like English. This is very common when learning prepositions and time expressions: it is better to learn the Italian phrase as a whole.