Mi jornada de trabajo termina a las cuatro, así que estudio español por la tarde.

“Jornada de trabajo” literally means “workday” or “working shift” — the period of hours you work (for example, 9–5).

• “trabajo” by itself is more general: it can mean my job, my work, or the act of working.
• “día de trabajo” is closer to workday as a calendar day, but “jornada de trabajo” focuses more on the hours/schedule of that day.
  In many contexts in Latin America, “jornada de trabajo” sounds a bit more formal or technical (e.g., in contracts, labor law), but it’s perfectly natural in normal speech too.

Here, “termina” is just the normal verb “terminar” in 3rd person singular (it ends / it finishes), with “mi jornada de trabajo” as the subject.

• “se termina” (reflexive) can also be used, but it’s a bit more colloquial and can sound more like “it comes to an end.”
• “acaba” or “finaliza” would also be correct; they’re near-synonyms of “termina”.
  So you could also say “Mi jornada de trabajo acaba a las cuatro” or “finaliza a las cuatro” with essentially the same meaning.

Grammatically, “termina” is present tense: my workday ends at four.
Spanish, like English, often uses the simple present for scheduled or habitual events in the future or every day:

• El tren sale a las ocho. – The train leaves at eight.
• Mi jornada de trabajo termina a las cuatro. – My workday ends at four.
  So it’s present tense, but it can describe something that regularly happens or is scheduled.

In time expressions, “a” corresponds to “at”:

• a la una – at one o’clock
• a las cuatro – at four o’clock

So “termina a las cuatro” literally means it ends *at four. The preposition for clock time is *“a”, not “en” or another preposition.

Spanish normally includes the definite article with clock time:

• las tres (the three)
• las cuatro (the four)
• la una (the one – singular because “una” is 1:00)

Literally, “las cuatro” is the four (o’clock). It feels incomplete to say just “cuatro” for time; you expect “las cuatro” in full sentences like:

• Llego a las cuatro. – I arrive at four.

The article agrees with an implied feminine noun: “las cuatro (horas)” or “las cuatro (en punto)”.
The word “hora” (hour) is feminine, so the article is “la/las”:

• la una (hora)
• las cuatro (horas)

That’s why you always see la una, las dos, las tres, etc., when talking about time.

Yes, “Mi jornada de trabajo termina a las cuatro de la tarde” is perfectly correct.

• “a las cuatro” – just at four (o’clock); the context may already make it clear whether it’s morning or afternoon.
• “a las cuatro de la tarde” – at four in the afternoon; more specific.

Your original sentence already mentions “por la tarde” later, so adding “de la tarde” at the beginning would be a bit redundant, but still grammatical.

“así que” means “so” / “so that / therefore” and introduces a consequence:

• Termina a las cuatro, así que estudio español. – It ends at four, so I study Spanish.

You could also say:

• …por eso estudio español. – for that reason I study Spanish (slightly more formal/logical).
• …entonces estudio español. – then I study Spanish (a bit more like a next step in a sequence).

In everyday speech, “así que” is very common and natural to express a result or consequence.

Both are possible, but they’re not used in exactly the same way.

• “estudio español por la tarde” (simple present) usually means a habit or routine: I study Spanish in the afternoons (regularly).
• “estoy estudiando español por la tarde” (present progressive) focuses more on what you’re doing around this time period, maybe temporarily: These days I’m studying Spanish in the afternoons.

In Spanish, the simple present is used more often for habits than the progressive is, compared with English.

Spanish verb endings already indicate the subject, so the pronoun is usually dropped:

• (Yo) estudio. – I study.
• (Tú) estudias. – You study.

Here “estudio” clearly shows that the subject is “yo”, so “yo” is not necessary. You would add “yo” for emphasis or contrast, for example:

• Yo estudio español, pero él no. – I study Spanish, but he doesn’t.

“por la tarde” means roughly “in the afternoon” / “during the afternoon” in a general sense.

• “por” here expresses a non-specific time period: sometime during the afternoon, as a general block of time.
• “en la tarde” is heard in parts of Latin America (e.g., some areas of Colombia, Central America) and can be natural locally, but “por la tarde” is more standard and widely accepted across the Spanish-speaking world.

So if you want a broadly neutral Latin American Spanish, “por la tarde” is the safest option.

Yes, “Por la tarde estudio español” is completely correct.

The basic meaning is the same: In the afternoon, I study Spanish.
Placing “por la tarde” at the beginning can slightly emphasize the time frame, but it doesn’t change the core meaning; it’s mainly a stylistic choice.

In Spanish, names of languages are written with lowercase:

• español, inglés, francés, alemán, japonés, etc.

So “estudio español” is correct, not “estudio Español”.
Capitals are used for nationalities as nouns in English (a Spaniard), but in Spanish, even those are typically lowercase too: un español, una mexicana.

“de trabajo” here functions like an adjective: work-related, working. It’s a general description, not referring to “the specific job” as a separate noun.

You use “del” only when “de + el” is really needed (meaning of the):

• el jefe del trabajo – the boss of the job
  But here we mean workday in general, so it’s just “jornada de trabajo”, without the article “el”.

The subject is the full phrase “Mi jornada de trabajo”.

• Mi – my (possessive adjective)
• jornada – day/shift (noun)
• de trabajo – of work / work-related (prepositional phrase modifying “jornada”)

So literally: “My workday ends at four.” The verb “termina” agrees with “jornada” (3rd person singular).

“mi” doesn’t show gender, only number. It stays the same for masculine or feminine singular:

• mi libro – my book (masculine)
• mi jornada – my workday (feminine)

In the plural, it becomes “mis”:

• mis libros – my books
• mis jornadas de trabajo – my workdays / my working shifts

Yes, some common alternatives with the same idea:

• Mi horario de trabajo termina a las cuatro, así que estudio español por la tarde.
• Salgo del trabajo a las cuatro, así que estudio español por la tarde. – I leave work at four…
• Trabajo hasta las cuatro, así que estudio español por la tarde. – I work until four…

All of these would sound natural in Latin America, with slightly different nuances (schedule vs leaving vs working hours).