Ieri am tăiat morcovii cu cuțitul nou și i-am pus în tigaie.

This is the very common Romanian compound past (perfectul compus).

It is built with:

• the auxiliary a avea in the present
• plus the past participle

So:

• am tăiat = I/we cut / have cut
• am pus = I/we put / have put

In everyday Romanian, this is the normal way to talk about completed past actions, especially in speech.

In Romanian, the definite article is usually attached to the end of the noun, not placed before it as in English.

So:

• morcovi = carrots
• morcovii = the carrots

and:

• cuțit = knife
• cuțitul = the knife

That is one of the biggest differences from English: Romanian often says noun + attached the.

Because both the plural ending and the definite article are showing up.

For morcov:

• singular: morcov = carrot
• plural: morcovi = carrots
• definite plural: morcovii = the carrots

So the two i letters do different jobs:

• first i = plural
• second i = definite article

This is very common with masculine nouns in the plural.

Yes, but here cu means with in the sense of using something as an instrument.

So:

• cu cuțitul nou = with the new knife
• meaning: the knife is the tool used to cut

Romanian cu can mean:

• accompaniment: cu Maria = with Maria
• instrument: cu cuțitul = with the knife

The context tells you which meaning is intended.

Here i- means them and refers back to morcovii.

So:

• i-am pus = I put them

Romanian often avoids repeating the noun and uses a short object pronoun instead.

Also, these short object pronouns usually go before the verb or auxiliary, not after it. So Romanian says the equivalent of:

• them I-put

rather than repeating morcovii again.

Because morcovi is a masculine plural noun, and the direct-object clitic for masculine plural is i-.

So:

• morcovii → i-am pus = I put them

If the noun were feminine plural, you would normally use le.

This is based on grammatical gender, not real-world gender. Even inanimate things can be masculine, feminine, or neuter in Romanian.

The hyphen links the unstressed object pronoun i- to the auxiliary am.

This is standard Romanian spelling with clitic pronouns in forms like:

• l-am
• i-am
• m-am
• te-am

So the hyphen is not optional here; it is the normal written form.

With a pune (to put), în usually means into, because the verb itself shows movement.

So:

• am pus în tigaie = I put into the pan

Romanian often uses în for both English in and into. The verb tells you whether the meaning is static or directional.

As for tigaie without the definite article:

• în tigaie is very natural in cooking contexts
• it can sound like into the pan or into a pan, depending on context

If you want to make the pan more specifically identified, you can say things like:

• în tigaia asta = into this pan
• în tigaia mare = into the big pan

Yes, it could go somewhere else. Romanian word order is fairly flexible.

Putting ieri first is very natural because it sets the time right away:

• Ieri am tăiat morcovii... = Yesterday, I cut the carrots...

You could also say:

• Am tăiat ieri morcovii...

That is also correct, but the emphasis is a little different. Starting with ieri highlights the time frame first.

Strictly speaking, am tăiat by itself can mean either I cut or we cut, because the auxiliary am is used with both eu and noi in the compound past.

So in isolation, the form is ambiguous:

• eu am tăiat = I cut
• noi am tăiat = we cut

Usually the context makes it clear. If the speaker wants to remove ambiguity or add emphasis, they can include the subject:

• Eu am tăiat...
• Noi am tăiat...

So in your sentence, the meaning I cut comes from context, not from am alone.

Yes. Both are possible:

• cuțitul nou
• noul cuțit

Both mean the new knife.

The difference is mainly one of structure and style:

• cuțitul nou is the more neutral, very common pattern: noun + adjective
• noul cuțit puts the adjective first, and then the definite article appears on the adjective

So when the adjective comes before the noun, Romanian usually moves the definite article onto the adjective:

• noul cuțit
• not nou cuțitul

In this sentence, cuțitul nou is the most straightforward everyday wording.