Посылка весит два фунта.

Because посылка is the subject of the sentence: it is the thing that weighs something.

• посылка = package / parcel
• весит = weighs

So посылка stays in the nominative singular, which is the normal case for the subject.

весит is the 3rd person singular present form of the verb весить, meaning to weigh.

So:

• я вешу = I weigh
• ты весишь = you weigh
• он / она / оно весит = he / she / it weighs
• они весят = they weigh

In this sentence, посылка is singular, so the verb is singular too: весит.

Because два / две agrees with the noun being counted, and here the counted noun is фунт.

• фунт is masculine
• so you use два

Compare:

• два фунта = two pounds
• две книги = two books

A common source of confusion is that посылка is feminine, but that does not matter here. The numeral belongs with фунт, not with посылка.

After the numbers 2, 3, 4, Russian usually uses the noun in the genitive singular.

So:

• один фунт = one pound
• два фунта = two pounds
• три фунта = three pounds
• четыре фунта = four pounds
• пять фунтов = five pounds

That is why the sentence has два фунта.

This is one of the most important number patterns in Russian.

Here are the main patterns:

• Посылка весит один фунт.
• Посылка весит два фунта.
• Посылка весит три фунта.
• Посылка весит четыре фунта.
• Посылка весит пять фунтов.

So the noun changes depending on the number:

• 1 → nominative singular
• 2–4 → genitive singular
• 5+ → genitive plural

It can mean both:

• фунт = pound as a unit of weight
• фунт = pound as money, especially the British pound

Context tells you which meaning is intended. In Посылка весит два фунта, it clearly means the unit of weight.

Russian normally has no articles.

So посылка can mean:

• a package
• the package

The exact meaning depends on context. Russian speakers understand this from the situation, previous sentences, or emphasis.

Yes. Russian word order is fairly flexible because the grammar endings show each word’s role.

The neutral order here is:

• Посылка весит два фунта.

But you might also hear:

• Два фунта весит посылка.

That could sound more emphatic, like The package weighs two pounds with extra focus on two pounds.

Still, for learners, Посылка весит два фунта is the safest and most natural basic order.

A rough pronunciation guide is:

puh-SIL-kuh VYE-sit dva FOON-tuh

A few notes:

• посылка stresses the second syllable: посы́лка
• весит stresses the first syllable: ве́сит
• фунта stresses the first syllable: фу́нта

If you want the stressed forms:

• посы́лка
• ве́сит
• фу́нта

No. They look similar, but they mean different things:

• весить = to weigh
• висеть = to hang

So:

• Посылка весит два фунта. = The package weighs two pounds.
• Посылка висит на двери. = The package is hanging on the door.

This is a very common learner confusion, so it is worth remembering early.

Usually not if you mean package / parcel in the mailing or shipping sense.

• посылка = parcel, package sent by mail
• пакет = bag, packet, plastic bag, or sometimes a package in other contexts

So if you mean a mailed parcel, посылка is the best word here.