Sempre omplo la motxilla abans d'anar a la biblioteca.

In Catalan, sempre means always, and it is very commonly placed at the beginning of the sentence for emphasis or simply as a natural default order:

• Sempre omplo la motxilla... = I always fill my backpack...

You could also hear Omplo sempre la motxilla..., but that sounds less neutral in many contexts. Starting with sempre is very natural.

Omplo means I fill. It comes from the verb omplir, which means to fill.

So:

• omplir = to fill
• omplo = I fill

This is the 1st person singular present tense form.

Catalan verbs do not form the I form in the same way as Spanish or English patterns might make you expect.

For omplir:

• jo omplo = I fill
• tu omples = you fill
• ell/ella omple = he/she fills

So omplo is just the correct present-tense form. Many -ir verbs in Catalan have forms that may look a little irregular to English speakers at first.

Catalan often uses the definite article where English may not, especially with everyday nouns that refer to a specific thing in context.

• la motxilla = the backpack

Here it refers to the speaker’s backpack, understood from context. Catalan normally includes the article:

• Omplo la motxilla
  not usually
• Omplo motxilla

This is similar to how Romance languages often use articles more regularly than English.

Abans means before, but when it is followed by a verb in the infinitive, Catalan uses abans de:

• abans d'anar = before going / before I go

So:

• abans = before
• abans de + infinitive = before doing something

Examples:

• abans de menjar = before eating
• abans de sortir = before leaving

This is because of elision. In Catalan, de becomes d' before a vowel sound.

So:

• de + anar → d'anar

This is very common:

• d'anar
• d'estudiar
• d'obrir

It works much like contractions in other Romance languages.

Yes, anar literally means to go, and here abans d'anar a la biblioteca means:

• before going to the library

Catalan often uses the infinitive after expressions like abans de. English may use either:

• before going to the library
• before I go to the library

Catalan uses the infinitive structure very naturally here.

A is the preposition to, and la biblioteca means the library.

So:

• anar a la biblioteca = to go to the library

Catalan uses a with destinations:

• anar a casa = to go home
• anar a l'escola = to go to school
• anar a la biblioteca = to go to the library

In standard Catalan, you would normally say a la biblioteca with the article.

• la biblioteca = the library

Catalan generally keeps the article with places like this more consistently than English does. So anar a la biblioteca is the normal form.

Usually, yes. Motxilla is the normal word for backpack or rucksack.

Depending on context, it can refer to:

• a school backpack
• a travel backpack
• a hiking backpack

In this sentence, backpack is the most natural translation.

In standard Catalan, omplir is the usual and preferred verb for to fill.

The form emplenar / empleno exists in some contexts and varieties, but omplir / omplo is the most common everyday choice here.

So for a learner, Sempre omplo la motxilla... is the safest and most natural option.

A helpful approximate pronunciation is:

SEM-pruh OM-ploo luh moot-SHEE-yuh uh-BANZ DA-NAR uh luh bee-blee-oh-TEH-kuh

A few notes:

• sempre: the e sounds are usually more neutral than in English
• omplo: the o in the stressed syllable is clear and rounded
• motxilla: tx sounds like ch, and ll in standard Central Catalan sounds like the y in yes
• d'anar links smoothly together
• biblioteca has the stress on te

Yes, you can say:

• Jo sempre omplo la motxilla abans d'anar a la biblioteca.

But Catalan usually leaves subject pronouns out unless they are needed for emphasis, contrast, or clarity. Since omplo already means I fill, jo is unnecessary in a neutral sentence.

So the original sentence sounds more natural in most situations.