L'offerta di lavoro include il bonus variabile e l'indennità.

Because offerta starts with a vowel, Italian usually shortens la to l' before feminine singular nouns that begin with a vowel.

• la casa
• l'offerta
• l'indennità

This is called elision. It makes the phrase sound smoother.

Di lavoro means of work / for work, and together offerta di lavoro is the normal Italian way to say job offer.

Italian often uses noun + di + noun where English uses a compound noun:

• offerta di lavoro = job offer
• mercato del lavoro = job market / labor market
• contratto di lavoro = employment contract

So even though English says job offer, Italian naturally says offer of work.

Because in offerta di lavoro, lavoro is being used in a general, fixed expression. Italian often leaves out the article after di in expressions like this.

Compare:

• un'offerta di lavoro = a job offer
• il contratto di lavoro = the employment contract

If you added an article here, it would usually change the meaning or sound less natural in this expression.

Because the subject is L'offerta di lavoro, which is third person singular.

The verb includere in the present tense goes like this:

• io includo = I include
• tu includi = you include
• lui/lei include = he/she/it includes
• noi includiamo = we include
• voi includete = you all include
• loro includono = they include

So L'offerta di lavoro include... means The job offer includes...

In Italian, nouns usually need an article when they are specific items in a sentence like this.

So:

• il bonus variabile
• l'indennità

This sounds natural because the sentence is talking about particular parts of the offer. English often drops articles more easily, but Italian usually keeps them.

Yes, bonus is normally treated as masculine in Italian, so it takes il in the singular:

• il bonus
• i bonus

It is a loanword, and its plural usually stays unchanged: bonus.

So:

• il bonus variabile = the variable bonus
• i bonus variabili = the variable bonuses

Because in Italian, adjectives often come after the noun.

So:

• bonus variabile
• stipendio mensile
• contratto stabile

English usually puts adjectives before the noun, but Italian very often puts them after. In this sentence, variabile describes the type of bonus.

For the same reason as l'offerta: indennità begins with a vowel, so la becomes l'.

• la pensione
• l'indennità

This is the standard form in Italian.

Indennità is a feminine noun meaning something like an allowance, compensation, or indemnity, depending on context.

The written accent on -tà shows where the stress falls:

• inden-ni-tà

This is very common in Italian nouns ending in -tà:

• città
• università
• necessità
• indennità

These nouns are usually feminine.

It actually already agrees with bonus in the correct form.

Variabile is an adjective that has the same form for masculine singular and feminine singular in many cases. Its plural changes to variabili.

So you get:

• il bonus variabile
• la parte variabile
• i bonus variabili
• le parti variabili

In this sentence, variabile is singular because bonus is singular.

Yes. Comprendere is a good alternative and often sounds a bit more formal or polished.

• L'offerta di lavoro include il bonus variabile e l'indennità.
• L'offerta di lavoro comprende il bonus variabile e l'indennità.

Both are correct. Include is very common and straightforward.

A natural pronunciation would be roughly:

Loffèrta di lavóro inclùde il bònus variàbile e lindennità.

A few notes:

• L'offerta sounds almost like lofferta
• include is stressed on -clu-
• indennità is stressed on the final -tà
• e is usually pronounced like eh

You do not pause between l' and the following word.