Learn Hardcore Indonesian: Judul yang dosen usulkan kemarin terasa terlalu panjang bagi saya. - The title that the lecturer suggested yesterday feels too long for me.

Judul yang dosen usulkan kemarin literally: “the title that the lecturer proposed yesterday”.
Yang here is similar to English that/which in phrases like “the book that I bought”.
The whole chunk yang dosen usulkan kemarin functions like an adjective, specifying which title.

Why is it dosen usulkan and not dosen mengusulkan?

The underlying basic sentence is: Dosen mengusulkan judul itu kemarin (The lecturer proposed the title yesterday).

When the object judul is moved to the front and becomes the head of a relative clause (judul yang …), Indonesian often drops the meN- prefix on the verb:

Basic: dosen mengusulkan judul itu
Relative: judul yang dosen usulkan

You can say judul yang dosen mengusulkan kemarin, and it is grammatically correct, but in everyday usage the version with the bare verb (usulkan) is very common and sounds natural.

Could we say judul yang diusulkan dosen kemarin instead? What is the difference?

Yes, judul yang diusulkan dosen kemarin is also correct.

yang dosen usulkan = active pattern, the lecturer is clearly the doer.
yang diusulkan dosen = passive pattern, the title is the grammatical focus.

In meaning, both are effectively “the title (that) the lecturer proposed yesterday”. The difference is stylistic: the passive yang diusulkan dosen can sound a bit more formal or written, but both are widely used.

What is the base word of usulkan, and what does the suffix -kan do here?

The base word is usul, which can be a noun (suggestion, proposal) or verb-like (to suggest/propose).

usul → base: suggestion / to suggest
usulkan (with -kan) → “to put forward a suggestion”, “to propose something to someone”

In practice, mengusulkan (sesuatu) means to propose/put forward (something). In the relative clause, after moving the object, mengusulkan surfaces as usulkan.

What exactly does terasa mean here, and how is it different from merasa?

Terasa is from rasa (feel), and here it means “feels / seems (to the senses or subjectively)”.

Judul … terasa terlalu panjang = The title feels/seems too long (from my perspective).

Merasa is used when the subject is the person who feels something:

Saya merasa judul itu terlalu panjang = I feel (that) the title is too long.

So:

terasa → the thing has a certain feel (judulnya terasa panjang)
merasa → someone feels something (saya merasa…)

Could we remove terasa and just say Judul yang dosen usulkan kemarin terlalu panjang bagi saya?

Yes, that sentence is grammatically correct.

With terasa: Judul … terasa terlalu panjang bagi saya → emphasizes your subjective perception: it feels too long to you.
Without terasa: Judul … terlalu panjang bagi saya → more like a direct statement “is too long for me”, a bit more neutral and factual.

Both are natural; terasa simply adds the nuance of personal impression.

What is the nuance of bagi saya? How is it different from menurut saya, untuk saya, or buat saya?

Bagi saya literally means for me / as far as I am concerned, with a focus on the effect or relevance to you.

Roughly:

bagi saya → for me, from my standpoint / in terms of how it affects me
menurut saya → in my opinion (more about judgment, less about direct effect)
untuk saya → for me (often purpose, allocation: ini untuk saya? = is this for me?)
buat saya → informal “for me” (colloquial alternative to untuk/bagi saya)

In this sentence, bagi saya nicely combines the idea of opinion and personal impact: the title is excessively long from my point of view / for my taste.

How is past time expressed here? There is no verb tense like in English.

Indonesian verbs do not change form for tense. Time is usually shown by context or by time adverbs.

In this sentence, kemarin (yesterday) is the only marker that shows the proposal happened in the past.

Without kemarin, the sentence could be about a title that is generally proposed (no specific time).
With kemarin, it clearly refers to a proposal made yesterday.

Where does kemarin belong exactly? Is it modifying usulkan or the whole sentence?

Functionally, kemarin goes with the action usulkan: dosen usulkan (judul itu) kemarin.

In the relative clause, it is normal to place time expressions like kemarin at the end of that clause:

judul yang dosen usulkan kemarin ≈ the title that the lecturer proposed yesterday

You could also say judul yang kemarin dosen usulkan, but judul yang dosen usulkan kemarin is more common and feels smoother.

Is judul here definite (like “the title”) or indefinite (like “a title”)?

In natural English translation it is “the title”, because the relative clause yang dosen usulkan kemarin makes it specific: it refers to a particular title that both speaker and listener can identify.

Indonesian does not have articles like a/the, so definiteness is often shown by context. If you wanted to emphasize it even more, you could say:

Judul yang dosen usulkan kemarin itu terasa terlalu panjang bagi saya.

Here itu clearly marks it as a specific, known title.

What is the difference between terlalu panjang and sangat panjang?

terlalu panjang = too long, excessively long (normally implies a negative judgment or that it goes beyond what is acceptable).
sangat panjang = very long (strong degree but not automatically “too much”; it can be neutral or even positive depending on context).

In this sentence, terlalu panjang fits well, because you are complaining that the length is more than you can accept.

How formal is this sentence, and how might it sound in more casual Indonesian?

The original sentence is neutral-to-formal, suitable for academic or polite contexts: dosen, usulkan, bagi saya all sound reasonably standard and polite.

A more casual version might be something like:

Judul yang dosen kasih kemarin kerasa kepanjangan buat saya.

Here:

kasih instead of usulkan (colloquial give/suggest)
kerasa instead of terasa
kepanjangan (colloquial too long)
buat saya instead of bagi saya (more informal)

Your original form is perfectly natural in a university context.