Diese Technologie ist nützlich.

Diese means this.

It has this form because Technologie is a feminine noun in German, and the sentence uses the nominative case because Technologie is the subject.

So:

• der = masculine
• die = feminine
• das = neuter

And the corresponding this forms in the nominative are:

• dieser = this (masculine)
• diese = this (feminine)
• dieses = this (neuter)

Since Technologie is feminine, you say diese Technologie.

Technologie is feminine.

You can tell from the dictionary form: die Technologie.

That is why the sentence uses:

• diese Technologie

and not:

• dieser Technologie
• dieses Technologie

In German, all nouns are capitalized, not just proper names.

So Technologie starts with a capital T because it is a noun.

Examples:

• das Buch
• die Stadt
• die Technologie

This is a normal rule in written German.

Ist means is.

It is the third-person singular form of the verb sein = to be.

The present tense of sein is:

• ich bin = I am
• du bist = you are
• er/sie/es ist = he/she/it is
• wir sind = we are
• ihr seid = you are
• sie/Sie sind = they are / you are (formal)

Since Technologie is singular, the sentence uses ist.

Because German main clauses usually follow the verb-second rule, often called V2.

In a normal statement, the finite verb comes in the second position:

• Diese Technologie ist nützlich.

Here:

1. Diese Technologie = first element
2. ist = second element
3. nützlich = rest of the sentence

This is one of the most important word-order rules in German.

Because nützlich is being used as a predicate adjective, not an adjective directly before a noun.

After verbs like sein (to be), adjectives usually do not change their form.

So you say:

• Diese Technologie ist nützlich.
• Das Buch ist interessant.
• Die Autos sind teuer.

But when an adjective comes before a noun, it usually takes an ending:

• eine nützliche Technologie
• ein interessantes Buch
• teure Autos

So:

• ist nützlich = no adjective ending
• eine nützliche Technologie = adjective ending needed

Yes. The subject diese Technologie is in the nominative case.

In this sentence:

• Diese Technologie = subject, so nominative
• ist = linking verb
• nützlich = predicate adjective

There is no accusative, dative, or genitive noun phrase here.

Yes, but the meaning changes slightly.

• Diese Technologie ist nützlich = this technology is useful
• Die Technologie ist nützlich = the technology is useful

So diese points to a specific thing near the speaker or already being referred to, while die is just the definite article the.

Also, you do not say:

• die diese Technologie

because diese already works like a determiner, so it replaces the article.

The word nützlich is pronounced approximately like NYOOTS-likh, but that English approximation is not perfect.

A few pronunciation points:

• ü is a front rounded vowel that English does not really have
• tz sounds like ts
• ch here is the softer German ich-Laut, not the English ch in church

A helpful approximation:

• say ee as in see
• keep your tongue in that position
• round your lips as if saying oo

That gets you closer to ü.

So nützlich is not pronounced like nootzlich or nutzlich.

Usually yes, but usage can vary a little depending on context.

Technologie often means:

• technology in general
• a technology
• a technical method or system

In many contexts, it matches English technology very closely.

Examples:

• moderne Technologie = modern technology
• neue Technologien = new technologies

Its main meaning is useful.

Depending on context, English might sometimes translate it as helpful, but useful is the most direct match.

Related words:

• nützlich = useful
• hilfreich = helpful
• praktisch = practical / handy

So in many situations, nützlich and hilfreich are close, but they are not always exactly the same.

Yes, but the verb still has to stay in the second position in a normal main clause.

Standard order:

• Diese Technologie ist nützlich.

You could also say:

• Nützlich ist diese Technologie.

That version is more marked or stylistic, because it emphasizes nützlich.

So the word order can change, but the conjugated verb ist still stays in second position.

The plural would be:

• Diese Technologien sind nützlich.

Changes:

• Technologie → Technologien = technologies
• ist → sind = are
• nützlich stays the same, because it is still a predicate adjective

So:

• singular: Diese Technologie ist nützlich.
• plural: Diese Technologien sind nützlich.