A la primavera, anem al bosc i hi ha molta aigua al riu.

In Catalan, time expressions with seasons are very often introduced by a:

• a la primavera = in spring
• a l’estiu = in summer
• a la tardor = in autumn
• a l’hivern = in winter

So although English uses in, Catalan commonly uses a here. You should learn a la primavera as a normal fixed way to say in spring.

Because primavera is a feminine singular noun in Catalan, so it takes the feminine singular article la:

• la primavera
• la tardor

Not all seasons behave the same way in every language, so it is best to memorize the gender with the noun.

Anem means we go or we are going, depending on context. It comes from the verb anar = to go.

Present tense of anar:

• vaig = I go
• vas = you go
• va = he/she/it goes
• anem = we go
• aneu = you all go
• van = they go

So in the sentence, anem al bosc = we go to the forest.

Catalan often drops subject pronouns because the verb ending already shows who the subject is. Since anem clearly means we go, nosaltres is usually unnecessary.

You could say:

• Nosaltres anem al bosc

but that would usually add emphasis or contrast, like we go to the forest.

Because a + el contracts to al in Catalan.

So:

• a + el bosc → al bosc
• a + el riu → al riu

This is very common. Similar contractions happen in other Romance languages too.

Here it means to the forest after the verb anar:

• anem al bosc = we go to the forest

With anar, Catalan uses a to mark destination.

Hi ha means there is or there are.

Examples:

• Hi ha un llibre. = There is a book.
• Hi ha molts llibres. = There are many books.

In your sentence:

• hi ha molta aigua al riu = there is a lot of water in the river

In hi ha, the hi is part of a fixed expression meaning there is/there are. For learners, it is best to treat hi ha as a whole unit.

Catalan also uses hi in other ways as a locative pronoun, often meaning something like there or in/at it, but in hi ha, you should first learn the full expression as the normal way to say there is/there are.

Because aigua is grammatically feminine, and molt must agree with it:

• masculine singular: molt
• feminine singular: molta
• masculine plural: molts
• feminine plural: moltes

So:

• molta aigua = a lot of water

Even though water is uncountable in English, Catalan still treats aigua as a feminine singular noun, so the adjective/determiner must match it.

Because Catalan usually uses l’ before a vowel sound:

• l’aigua = the water

In your sentence there is no article before aigua, because it is part of the expression molta aigua = a lot of water, not the water.

So compare:

• l’aigua = the water
• molta aigua = a lot of water

Here al riu means in the river, not to the river.

This can feel strange to English speakers, because Catalan often uses a in places where English uses in or at, especially with locations after certain expressions.

So:

• hi ha molta aigua al riu = there is a lot of water in the river

The exact meaning comes from the whole sentence, not just the preposition by itself.

Yes. The present tense in Catalan, like in English, can describe:

• something happening now
• something habitual or repeated
• a general truth

So A la primavera, anem al bosc i hi ha molta aigua al riu can naturally mean something like:

• In spring, we go to the forest and there is a lot of water in the river

This sounds like a habitual or seasonal statement.

Yes, Catalan has some flexibility, but this order is very natural.

The sentence begins with the time expression:

• A la primavera = in spring

Then comes the main statement:

• anem al bosc = we go to the forest
• i hi ha molta aigua al riu = and there is a lot of water in the river

Starting with the time phrase is common because it sets the scene first. You could move things around in some contexts, but the given version is normal and clear.

Because A la primavera is an introductory time phrase. In writing, Catalan often puts a comma after this kind of opening element, especially when it sets the scene for the rest of the sentence.

So the comma helps separate:

• A la primavera,
  from
• anem al bosc i hi ha molta aigua al riu

Yes. Hi ha stays the same for both singular and plural.

Examples:

• Hi ha un arbre. = There is a tree.
• Hi ha dos arbres. = There are two trees.

So unlike English there is / there are, Catalan uses the same form hi ha in both cases.

Bosc usually means forest, woodland, or woods, depending on context. English chooses among those words based on style and situation, but Catalan commonly uses bosc for that general idea.

So anem al bosc could be translated as:

• we go to the forest
• we go to the woods

depending on the tone you want in English.