Learn Hardcore Russian: В конце семестра учёба иногда кажется тяжёлой, но я рад, когда вижу хорошую оценку в электронном журнале. - At the end of the semester studying sometimes feels hard, but I am glad when I see a good grade in the online gradebook.

конце is the prepositional case of конец (end).
- Masculine noun конец → prepositional singular в конце = at the end.
семестра is the genitive case of семестр (semester).
- After конец you usually put the thing that ends in the genitive:
  - конец дня – the end of the day
  - конец фильма – the end of the film
  - конец семестра – the end of the semester

So the literal structure is:
в (конце (семестра)) = in the end of the semester / at the end of the semester.

Why is it учёба кажется тяжёлой and not учёба кажется тяжёлая?

This is a typical Russian pattern:
подлежащее (subject in nominative) + сказуемое (predicate) in instrumental with verbs like быть, становиться, казаться.

учёба – nominative feminine singular
кажется – verb казаться (to seem) in 3rd person singular
тяжёлой – instrumental feminine singular of тяжёлый

With казаться meaning to seem (to be) something, Russian often uses instrumental for the “something”:

Учёба кажется тяжёлой. – Studying seems difficult.
Он кажется уставшим. – He seems tired.
Это кажется странным. – This seems strange.

So тяжёлой is in the instrumental to indicate a temporary or perceived quality.

What is the difference between тяжёлый, трудный, and сложный? Why use тяжёлой here?

All three can be translated as hard/difficult, but they have nuances:

тяжёлый – literally heavy; emotionally or physically heavy / burdensome.
- тяжёлая работа – hard, tiring work
- тяжёлый день – a hard day (emotionally/physically)
трудный – difficult because it requires effort or skill.
- трудная задача – a difficult task
- трудный экзамен – a difficult exam
сложный – complicated, complex (many parts, not simple).
- сложная тема – a complex topic
- сложная ситуация – a complicated situation

In учёба кажется тяжёлой, the focus is on the burden and feeling of heaviness at the end of the semester, not just intellectual difficulty. трудной or сложной would also be possible, but they shift the nuance more toward difficult to do/understand rather than weighing you down.

Why is иногда placed after учёба? Could I say Иногда учёба кажется тяжёлой?

Yes, you can absolutely say Иногда учёба кажется тяжёлой.

Russian word order is quite flexible. In this sentence:

Учёба иногда кажется тяжёлой – neutral statement; иногда is in the middle, slightly emphasizing the verb phrase.
Иногда учёба кажется тяжёлой – more natural in conversation; puts more emphasis on the fact that this doesn’t happen all the time.

Both are correct. Adverbs like иногда can appear in several positions without changing the core meaning. The chosen order feels natural and slightly emphasizes учёба as the topic.

Why is it я рад, not я радуюсь, and what is the difference?

рад is a short-form adjective; радоваться is a verb.

я рад – literally I am glad, a state or feeling.
- Я рад, когда вижу хорошую оценку. – I’m glad when I see a good grade.
я радуюсь – I rejoice / I am rejoicing, more active and expressive.
- Я радуюсь, когда вижу хорошую оценку. – I rejoice when I see a good grade (sounds more emotional).

Short-form рад is very common and neutral for “glad, happy (about something)”:

Я рад тебя видеть. – I’m glad to see you.
Он рад результатам. – He is glad about the results.

So я рад here is the most natural, calm way to say I’m glad.

Why is it я рад, когда вижу… and not я рад, что вижу…? Are both possible?

Both are grammatically correct, but the nuance is different:

я рад, когда вижу хорошую оценку
- emphasizes the situation/time: Whenever I see a good grade, I feel glad.
я рад, что вижу хорошую оценку
- emphasizes the fact: I’m glad that I see a good grade (now / in this case).

With когда, it sounds more like a general pattern or repeated situation. With что, it describes being happy about a specific fact. In this sentence, the context is recurring (end of each semester), so когда fits very well.

Why do we use вижу and not смотрю or увижу in я рад, когда вижу хорошую оценку?

The verbs differ in meaning:

видеть / видеть → вижу – to see (perceive with eyes, not necessarily intentionally).
- Я вижу хорошую оценку. – I see a good grade.
смотреть (на) – to look (at), an intentional action.
- Я смотрю на оценку. – I am looking at the grade.
увидеть – perfective of видеть, to see (at some specific moment, once).
- Я увижу хорошую оценку. – I will see a good grade (at some point).

Here we want the general situation: any time he sees (perceives) a good grade, he feels glad. That’s why:

imperfective present вижу is used,
and видеть, not смотреть, because the focus is on the result of perception, not on deliberately looking.

Why is it хорошую оценку with -ую and -у endings?

оценка (grade/mark) is a feminine noun:

nominative singular: оценка
accusative singular: оценку

In вижу хорошую оценку, оценку is the direct object of вижу, so it must be in the accusative.

The adjective хороший must agree with оценка in gender, number, and case:

feminine, singular, accusative: хорошую

So we get:

хорошая оценка – a good grade (subject, nominative)
вижу хорошую оценку – (I) see a good grade (object, accusative)

Why is электронном журнале in -ом and -е? What cases are those?

The phrase is в электронном журнале.

журнал → журнале is prepositional singular.
- Used after в when it means in / inside (location).
- в журнале – in the journal.
электронный → электронном is prepositional masculine singular, agreeing with журнале.

Pattern:

в + prepositional case for location:
- в доме – in the house
- в книге – in the book
- в электронном журнале – in the electronic journal/gradebook

So both электронном and журнале are in the prepositional case.

But doesn’t журнал mean “magazine”? How does электронный журнал mean gradebook?

Yes, журнал can mean magazine, but it also means journal / log / register. In the school context:

классный журнал – class register (teachers record attendance and grades)
электронный журнал – its electronic / online version

So in this sentence, электронный журнал is the online gradebook system where a student can see their grades, not an electronic magazine. The meaning comes from the school context, not just the dictionary translation.

Why is it в электронном журнале and not на электронном журнале?

The choice of в vs на with places is largely fixed by usage in Russian.

в журнале – means in the journal, i.e. inside its contents (pages/entries).
на журнале – literally “on top of the journal” (physically lying on it).

Since the grade is inside the record / database, Russian uses в журнале, just like:

в книге – in the book
в списке – in the list
в документе – in the document

So в электронном журнале describes where the grade is recorded, not where something lies physically.

Why is it в конце семестра and not к концу семестра? What’s the difference?

Both exist but mean different things:

в конце семестра – at the end of the semester, at that time point.
- Time location: When? At the end.
к концу семестра – by the end of the semester, by that time, as a deadline or gradual approach.
- Time limit or result: By when? By the end.

In this sentence, we’re talking about how studying feels at that period (the end of the semester), so в конце семестра (time when) is appropriate. К концу семестра would emphasize a process leading up to that point.

Is кажется here like English “it seems” (impersonal), or does it literally mean “studying seems”?

In this sentence, it is literal:

учёба кажется тяжёлой – studying seems hard.

There is also an impersonal use of кажется like English “it seems”:

Кажется, будет дождь. – It seems (that) it will rain.
Мне кажется, он устал. – It seems to me that he is tired.

Here, however, учёба is the clear, grammatical subject, so it is not the impersonal “it seems”, but “studying seems (to be) hard.”