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To defend in Irish (cosain): Meaning, Conjugation, Examples

Other uses of ‘cosain’: cost · earn

The Irish for to defend is cosain; ag cosaint is defending.
Updated October 2026Report a mistake

How to say “to defend” in Irish

Irish:
cosain
English:
to defend, cost, earn
Word type:
verb, second-conjugation
Verbal noun:
cosaint (ag cosaint, defending)
Verbal adjective:
cosanta
Pronunciation:
“KUSS-in”  /ˈkɔsənʲ/

What does “cosain” mean?

“Cosain” has three alternative meanings. The most common comes first.

to defend
To defend or protect someone or something against harm or attack.Also: protect, guard, shield.
2 other meanings: cost or earn
2to cost
To have a certain price or to require a certain amount to buy.Also: be priced at.
3to earn
To earn or merit something through effort.Also: merit, win.

“Cosain” in the different tenses

Every form follows An Caighdeán Oifigiúil.

Aimsir Chaite (Past)

PersonPositiveNegativeQuestion
mé (I)Chosain méI defendedNíor chosain méI did not defendAr chosain mé?Did I defend?
tú (you)Chosain túYou defendedNíor chosain túYou did not defendAr chosain tú?Did you defend?
sé / sí (he / she)Chosain sé / síHe defendedNíor chosain sé / síHe did not defendAr chosain sé / sí?Did he defend?
sinn (we)ChosnaíomarWe defendedNíor chosnaíomarWe did not defendAr chosnaíomar?Did we defend?
sibh (you, plural)Chosain sibhYou defendedNíor chosain sibhYou did not defendAr chosain sibh?Did you defend?
siad (they)Chosain siadThey defendedNíor chosain siadThey did not defendAr chosain siad?Did they defend?
saorbhriathar (autonomous)CosnaíodhNíor cosnaíodhAr cosnaíodh?

Aimsir Láithreach (Present)

PersonPositiveNegativeQuestion
mé (I)CosnaímI defendNí chosnaímI do not defendAn gcosnaím?Do I defend?
tú (you)Cosnaíonn túYou defendNí chosnaíonn túYou do not defendAn gcosnaíonn tú?Do you defend?
sé / sí (he / she)Cosnaíonn sé / síHe defendsNí chosnaíonn sé / síHe does not defendAn gcosnaíonn sé / sí?Does he defend?
sinn (we)CosnaímidWe defendNí chosnaímidWe do not defendAn gcosnaímid?Do we defend?
sibh (you, plural)Cosnaíonn sibhYou defendNí chosnaíonn sibhYou do not defendAn gcosnaíonn sibh?Do you defend?
siad (they)Cosnaíonn siadThey defendNí chosnaíonn siadThey do not defendAn gcosnaíonn siad?Do they defend?
saorbhriathar (autonomous)CosnaítearNí chosnaítearAn gcosnaítear?

Aimsir Fháistineach (Future)

PersonPositiveNegativeQuestion
mé (I)Cosnóidh méI will defendNí chosnóidh méI will not defendAn gcosnóidh mé?Will I defend?
tú (you)Cosnóidh túYou will defendNí chosnóidh túYou will not defendAn gcosnóidh tú?Will you defend?
sé / sí (he / she)Cosnóidh sé / síHe will defendNí chosnóidh sé / síHe will not defendAn gcosnóidh sé / sí?Will he defend?
sinn (we)CosnóimidWe will defendNí chosnóimidWe will not defendAn gcosnóimid?Will we defend?
sibh (you, plural)Cosnóidh sibhYou will defendNí chosnóidh sibhYou will not defendAn gcosnóidh sibh?Will you defend?
siad (they)Cosnóidh siadThey will defendNí chosnóidh siadThey will not defendAn gcosnóidh siad?Will they defend?
saorbhriathar (autonomous)CosnófarNí chosnófarAn gcosnófar?

Modh Coinníollach (Conditional)

PersonPositiveNegativeQuestion
mé (I)ChosnóinnI would defendNí chosnóinnI would not defendAn gcosnóinn?Would I defend?
tú (you)ChosnófáYou would defendNí chosnófáYou would not defendAn gcosnófá?Would you defend?
sé / sí (he / she)Chosnódh sé / síHe would defendNí chosnódh sé / síHe would not defendAn gcosnódh sé / sí?Would he defend?
sinn (we)ChosnóimisWe would defendNí chosnóimisWe would not defendAn gcosnóimis?Would we defend?
sibh (you, plural)Chosnódh sibhYou would defendNí chosnódh sibhYou would not defendAn gcosnódh sibh?Would you defend?
siad (they)ChosnóidísThey would defendNí chosnóidísThey would not defendAn gcosnóidís?Would they defend?
saorbhriathar (autonomous)ChosnófaíNí chosnófaíAn gcosnófaí?

“Cosain” in a sentence: Irish examples

Past, present, future and conditional, with a negative and a question.

Chosain an leabhar sin fiche euro orm.
That book cost me twenty euro.
Cosnaíonn an mháthair a páistí i gcónaí.
The mother always protects her children.
Cosnóidh an t-arm an tír.
The army will defend the country.
Chosnódh sé níos mó i mBaile Átha Cliath.
It would cost more in Dublin.
Níor chosain sé mórán ar chor ar bith.
It didn't cost much at all.
Cé mhéad a chosnaíonn an ticéad?
How much does the ticket cost?

Other verbs in Irish

More everyday Irish verbs to learn next.

To defend in Irish: frequently asked questions

What is the Irish for to defend?

The Irish for to defend is cosain (pronounced “KUSS-in”). It is a second-conjugation verb; the verbal noun is cosaint.

What is the verbal noun of cosain?

The verbal noun of cosain is cosaint, used after ag for the continuous: ag cosaint (defending). The verbal adjective is cosanta.

How do you say cosain in the past and the future?

Past: Chosain mé; negative Níor chosain mé; question Ar chosain mé?. Future: Cosnóidh mé; negative Ní chosnóidh mé; question An gcosnóidh mé?.

What is the modh coinníollach of cosain?

The conditional (modh coinníollach) first person is Chosnóinn (I would defend); negative Ní chosnóinn; question An gcosnóinn?.

Does cosain have more than one meaning?

Yes. Cosain can mean to defend, to cost or to earn, depending on context; the first is the most common.

How do I say something cost me money?

Use the preposition ar: "Chosain sé deich euro orm" means "It cost me ten euro."

Which preposition means 'against' with cosain?

Use ar or ó, for example "cosain ar an bhfuacht" or "cosain ón bhfuacht", to protect from the cold.

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