Gamli skjárinn nýtist mér enn, þó að hann sé gamall.

Because Icelandic usually marks definiteness in two places when a noun has a preceding adjective:

• the noun takes the definite article as a suffix: skjárinn = the screen
• the adjective goes into its weak form: gamli = old in the form used before a definite masculine singular noun

So gamli skjárinn literally works like the old the-screen, even though in natural English we just say the old screen.

Gamli is the weak nominative singular masculine form of gamall.

It agrees with skjárinn, which is:

• masculine
• singular
• nominative
• definite

That is why you get:

• gamall skjár = an old screen / old screen
• gamli skjárinn = the old screen

Because the two adjectives are doing different jobs.

• gamli is an attributive adjective: it comes directly before the noun skjárinn
• gamall is a predicate adjective: it comes after hann sé and describes the subject hann

Predicate adjectives usually use the strong form, not the weak definite form. So:

• gamli skjárinn = the old screen
• hann sé gamall = he/it is old

Both adjectives refer to the same thing, but the grammar is different.

Nýtist is the 3rd person singular present tense of the verb nýtast.

A very natural meaning is:

• to be useful
• to come in handy
• to be of use

So Gamli skjárinn nýtist mér enn means something like:

• The old screen is still useful to me
• I still get use out of the old screen

This is a very Icelandic way of expressing usefulness.

Because nýtast takes the person who benefits in the dative case.

The pronoun forms are:

• ég = I
• mig = me, accusative
• mér = me, dative

So:

• Skjárinn nýtist mér = The screen is useful to me

You just have to learn that nýtast governs the dative.

Here enn means still.

So:

• nýtist mér enn = is still useful to me

In other contexts, enn can also mean yet, depending on the sentence. In this one, still is the best match.

Þó að means although, even though, or though.

It introduces a clause that contrasts with the main statement:

• Gamli skjárinn nýtist mér enn = the main idea
• þó að hann sé gamall = a contrasting idea: even though it is old

So the sentence says that the screen is still useful despite being old.

Because þó að commonly triggers the subjunctive in Icelandic.

The verb vera = to be has:

• er = present indicative
• sé = present subjunctive

After þó að, the subjunctive is very common and standard:

• þó að hann sé gamall = although it is old

So sé is not random; it is the expected form after this conjunction.

Because after a subordinating conjunction like þó að, Icelandic normally uses subordinate clause word order.

That means the subject often comes before the finite verb:

• þó að hann sé gamall

In main clauses, Icelandic is a verb-second language, so the finite verb often appears early. But in subordinate clauses introduced by words like þó að, the order is more like what you see here.

Skjárinn is:

• masculine
• singular
• nominative
• definite

You can tell this from both the noun form and the agreeing adjective gamli.

The basic noun is skjár = screen.
With the suffixed article, it becomes skjárinn = the screen.

It is nominative because it is the subject of the sentence.

Here it means it.

In Icelandic, nouns have grammatical gender, and skjár is masculine, so the pronoun referring back to it is hann.

That does not mean the screen is biologically male. It is just grammatical agreement:

• skjár = masculine noun
• therefore hann = it when referring to that noun

So in this sentence, hann is best translated as it.