Minä opiskelen biologiaa kotona illalla.

I study biology at home in the evening.

Breakdown of Minä opiskelen biologiaa kotona illalla.

• minä: I
• kotona: at home
• opiskella: to study
• illalla: in the evening
• biologia: the biology

Questions & Answers about Minä opiskelen biologiaa kotona illalla.

Why is the subject Minä used here? Can it be left out?

In Finnish, subject pronouns (like minä = I) are usually optional, because the verb ending already shows the person.

• Minä opiskelen biologiaa kotona illalla.
• Opiskelen biologiaa kotona illalla.

Both mean “I study biology at home in the evening.”

Including minä often adds emphasis (like English “I study biology…”), or is used when you contrast people:
Minä opiskelen, mutta hän lepää. – I study, but he/she rests.

What exactly is opiskelen grammatically?

Opiskelen is the 1st person singular present tense form of the verb opiskella (to study).

• Verb: opiskella
• Stem: opiskele-
• Personal ending for “I”: -n

So:

• minä opiskelen – I study / I am studying
• sinä opiskelet – you (sg) study
• hän opiskelee – he/she studies

The -n at the end marks the subject as “I”.

Does opiskelen mean “I study” or “I will study”?

Both, depending on context. Finnish usually has one present tense that covers:

• Present/habitual:
  Minä opiskelen biologiaa. – I study biology. / I’m a biology student.
• Near future / planned:
  Minä opiskelen biologiaa kotona illalla. – I’m going to study / I will study biology at home this evening.

There is no separate future tense; context and time expressions (like illalla = in the evening) give the future meaning.

Why is it biologiaa and not just biologia?

Biologiaa is the partitive singular form of biologia (biology).

Finnish uses the partitive case for many objects, especially when:

• the activity is ongoing, incomplete, or open-ended
• the thing is not a clearly bounded “whole” (for example, a school subject)

Studying biology is not usually seen as something you “completely finish” as a whole; it’s an ongoing process. That’s why:

• opiskelen biologiaa – I (am) study(ing) biology (in general, as a subject)

What’s the difference between biologiaa and biologian after opiskelen?

Both are grammatically possible but they sound different:

• opiskelen biologiaa – the normal, natural way to say
  “I study biology” / “I’m studying biology” (general, ongoing).

• opiskelen biologian – suggests a total, complete object.
  It can sound like “I will study all of biology (and finish it).”
  In real life this is unusual unless you mean something specific, like finishing a course or syllabus.

So, for talking about a subject you study, use biologiaa.

Why does biologiaa have two a’s at the end?

Because of how the partitive singular is formed.

For many words ending in -a / -ä, you add another -a / -ä for the partitive:

• omena → omenaa (an apple → some apple / apple (partitive))
• koira → koiraa (a dog → some dog / dog (partitive))
• biologia → biologiaa

The double aa means the vowel is long. In pronunciation, biologiaa has a longer final a than biologia.

What does kotona mean exactly, and how is it different from kotiin and kotoa?

All three come from koti (home), but they show different directions:

• kotona – at home (location, “where?”)
  Olen kotona. – I am at home.
• kotiin – (to) home (movement towards, “where to?”)
  Menen kotiin. – I go home.
• kotoa – from home (movement away, “from where?”)
  Lähden kotoa. – I leave home.

In your sentence, kotona answers “Where are you studying?” → at home.

Why is illalla used for “in the evening”? What case is that?

Illalla is the adessive singular form of ilta (evening).

The adessive case (ending -lla / -llä) is often used for times of day:

• aamu → aamulla – in the morning
• päivä → päivällä – in/at daytime
• ilta → illalla – in the evening
• yö → yöllä – at night

So illalla literally means something like “on the evening”, but it’s translated as “in the evening”.

Does the order biologiaa kotona illalla have to stay like that, or can I change it?

Finnish word order is fairly flexible, but there is a neutral pattern:

[Subject] [Verb] [Object] [Place] [Time]

So your sentence:

• Minä (S) opiskelen (V) biologiaa (O) kotona (Place) illalla (Time)

Other orders are possible, but they change emphasis. For example:

• Illalla opiskelen biologiaa kotona.
  Emphasizes “In the evening, that’s when I study…”
• Kotona opiskelen biologiaa illalla.
  Emphasizes “At home I study…”

The original order is the most neutral.

Why is there no separate word for “at” or “in” in this Finnish sentence?

Finnish usually uses case endings on nouns instead of prepositions like at, in, on.

In your sentence:

• kotona = at home (the -na ending carries the “at” idea)
• illalla = in the evening (the -lla ending carries the “in/at” idea)

So instead of adding extra words like at or in, Finnish changes the form of the noun to express location or time.