Nessuno deve subire questo danno.

Nessuno means no one / nobody here, and it is being used as an indefinite pronoun.

In this sentence, nessuno is the subject of the verb:

• Nessuno = no one
• deve subire = must suffer / must undergo
• questo danno = this harm / this damage

So grammatically, nessuno is not describing a noun; it stands on its own.

Because nessuno is grammatically singular in Italian.

Even though nessuno refers to zero people, Italian treats it like a singular subject, so the verb is singular too:

• Nessuno deve... = correct
• Nessuno devono... = incorrect

This is similar to English no one is, not no one are.

Because nessuno already carries the negative idea when it is placed before the verb.

So:

• Nessuno deve subire questo danno. = correct

When nessuno comes before the verb as the subject, you do not add non.

Compare this with cases where a negative word comes after the verb, where Italian often does use non:

• Non vedo nessuno. = I see nobody.

So the short answer is: nessuno before the verb does the negative job by itself.

Because dovere is a modal verb, and modal verbs in Italian are followed by the infinitive of the main verb.

So:

• deve = must
• subire = suffer / undergo

Together: deve subire = must suffer / must undergo

This works like:

• voglio andare = I want to go
• posso parlare = I can speak
• devo studiare = I must study

So after deve, you use subire, not subisce.

Subire often means to suffer, to undergo, or to be subjected to something, usually something negative.

In this sentence, it suggests experiencing harm in a passive or unwilling way.

Common examples:

• subire un torto = to suffer an injustice
• subire un danno = to suffer damage / undergo harm
• subire violenza = to suffer violence

So subire is stronger and more formal than simply avere or ricevere.

Because danno is a masculine singular noun.

So the demonstrative has to match it:

• questo danno = this damage / this harm
• questi danni = these damages / these harms
• questa would be for a feminine singular noun, so it cannot go with danno

Agreement is very important in Italian:

• masculine singular: questo
• feminine singular: questa
• masculine plural: questi
• feminine plural: queste

It is similar, but not always identical in usage.

Danno can mean:

• damage
• harm
• injury
• loss

Depending on context, questo danno could mean physical damage, financial damage, emotional harm, or general injury.

English damage is often uncountable, but Italian danno is often used as a countable noun:

• un danno = a damage / a harm / a loss
  In natural English, this is often translated more smoothly as harm or loss rather than a damage.

So learners should not expect a perfect one-to-one match with English damage.

Yes, but only when it comes before a masculine singular noun.

Examples:

• nessuno = nobody / no one
• nessun uomo = no man
• nessun problema = no problem

In your sentence, nessuno stands alone as a pronoun, so nessuno is the correct form.

You would not say:

• Nessun deve subire questo danno. = incorrect

because here it is not directly modifying a noun.

The word order is normal and clear:

• Nessuno = subject
• deve subire = verb phrase
• questo danno = object

So it follows a straightforward pattern:

subject + modal verb + infinitive + object

Italian can change word order for emphasis, but the given version is the most neutral and natural.

For example, a more emphatic alternative could be:

• Questo danno non deve subirlo nessuno.

That version puts more focus on questo danno, but it is structurally more advanced.

Deve is the third-person singular present indicative of dovere.

So it can mean:

• must
• has to
• sometimes should, depending on context

In this sentence, it expresses obligation or principle in the present:

• Nessuno deve subire questo danno.

Even though it is present tense, it often has a general meaning, like a rule or moral statement.

Yes. In most cases, both are fine English equivalents.

• nessuno = nobody
• nessuno = no one

The difference is mostly stylistic in English:

• nobody is slightly more informal
• no one is slightly more neutral or formal

Italian nessuno covers both.

It is fairly neutral and can sound somewhat formal because of the words subire and danno.

It does not contain any informal wording. It would fit well in:

• a serious conversation
• a speech
• a legal or social context
• a written statement

A more everyday sentence might use different wording depending on the exact situation, but this one is completely natural Italian.

No. Here nessuno means no one in a general sense, not specifically males.

Although it has a masculine-looking form, Italian often uses the masculine as the default grammatical form when referring to people in general.

So in this sentence, nessuno can refer to:

• men
• women
• any person at all

It is not limited to male people.