Þessi stutta skýring dugði mér ekki, en glósurnar þínar nýtast mér vel.

Because skýring is a feminine singular noun, and after a demonstrative like þessi, the adjective usually takes the weak form.

So the phrase breaks down like this:

• þessi = this
• stutta = short, feminine singular weak form
• skýring = explanation, feminine singular nominative

That is why stutta ends in -a here. If the adjective were in a different gender, number, or case, the form would change.

Dugði is the past tense, 3rd person singular of the verb duga.

The verb duga means things like:

• to be enough
• to suffice
• to do the job

So dugði mér ekki means literally something like was not enough for me.

Because the subject is Þessi stutta skýring (singular), the verb is also singular: dugði.

Because both duga and nýtast commonly take the person affected in the dative case.

So:

• mér = to/for me in the dative
• nominative ég = I
• dative mér = to/for me

In this sentence:

• skýring dugði mér ekki = the explanation was not enough for me
• glósurnar þínar nýtast mér vel = your notes are useful to me / for me

This is something English speakers often just have to learn with the verb: some Icelandic verbs require a dative pronoun where English would simply use me.

They are related in idea, but not the same.

• duga = to be enough, to suffice
• nýtast = to be useful, to come in handy, to serve a purpose

So the contrast in the sentence is very natural:

• This short explanation wasn’t enough for me
• but your notes are useful to me / help me a lot

In other words, the explanation failed to be sufficient, while the notes actually help.

Because glósurnar is the definite plural form of glósur.

• glósur = notes
• glósurnar = the notes

Icelandic usually adds the definite article to the end of the noun instead of using a separate word like the.

So glósurnar þínar is literally something like the notes yours, but in natural English that becomes your notes.

In Icelandic, possessive pronouns often come after the noun, especially when the noun is definite.

So:

• glósurnar þínar = your notes

This is a very common pattern. English speakers often expect the possessive first, but postposed possessives are perfectly normal in Icelandic.

A preposed possessive, such as þínar glósur, can exist, but it often sounds more marked or stylistically different. In everyday neutral phrasing, glósurnar þínar is very natural.

Because its subject is plural:

• glósurnar þínar = your notes

Since notes is plural, the verb must agree with it:

• singular: nýtist
• plural: nýtast

So glósurnar þínar nýtast mér vel means your notes are useful to me / serve me well.

The -st ending is the Icelandic middle voice ending.

This ending can have several functions in Icelandic. Depending on the verb, it may make the meaning:

• reflexive
• reciprocal
• passive-like
• or simply create a related verb with its own meaning

In this case, nýtast is best learned as its own verb meaning to be useful or to be of use.

It is related to nýta, which means to use or to make use of, but nýtast does not mean exactly the same thing. So it is better to memorize:

• nýta eitthvað = to use something
• eitthvað nýtist mér = something is useful to me

Because Icelandic often places short object pronouns like mér before sentence adverbs such as ekki.

So the order:

• dugði mér ekki

is very natural.

A helpful way to think about it is:

• dugði = verb
• mér = short dative pronoun
• ekki = not

English speakers often expect not to come earlier, but Icelandic word order follows its own rules. The sentence is not unusual at all as written.

Vel is an adverb meaning well.

Here it modifies nýtast, so:

• nýtast vel = to be useful / work well / serve well

So glósurnar þínar nýtast mér vel means that the notes are not just useful in a basic sense, but that they help well, effectively, or a lot.

That tense shift is completely possible and natural.

• dugði = past: the explanation was not enough
• nýtast = present: the notes are useful

This suggests something like:

• the explanation already failed to help,
• but the notes are useful now, or in general.

English does this too: That explanation didn’t help me, but your notes are really useful.

So the tense contrast is meaningful, not a mistake.

Usually, no. Icelandic often expresses the by attaching it to the noun.

For example:

• glósur = notes
• glósurnar = the notes

Also, with þessi (this), you do not need a separate definite article the way English might use one in some contexts. So:

• Þessi stutta skýring = this short explanation

There is no separate word equivalent to English the in front of the noun here.

A few useful points:

• Þ in Þessi is like th in thin
• ð in dugði is like the th in this, though in connected Icelandic speech it can be softer or less clearly pronounced
• ý in þínar and nýtast is pronounced like ee in see, but held as a distinct Icelandic vowel
• skýring begins with sk, but before a front vowel it sounds closer to sky with a sh-like quality to many learners’ ears

Very rough learner-friendly approximations:

• Þessi ≈ THESS-ih
• skýring ≈ SKEER-ing
• dugði ≈ DUG-thi / DUG-dhi depending on accent and how carefully it is spoken
• nýtast ≈ NEE-tast
• glósurnar ≈ GLOH-su-nar

These are only approximations, but they can help you get started.