The cost of living has increased significantly and my salary has not kept pace.
'Significativamente' = si-gni-fi-ca-ti-va-MEN-te; nine syllables; stress on the eighth.
Use when inflation or rising living costs have eroded your real purchasing power and you want to frame the raise as a cost-of-living adjustment rather than a merit increase.
'Costo della vita' (cost of living) is an objective, measurable argument. Separating a cost-of-living adjustment from a merit raise can help — you may get the first even if the second is refused. In Italy, ISTAT publishes official inflation figures you can cite.
L'ISTAT riporta un'inflazione del [X]% negli ultimi due anni.
ISTAT reports inflation of [X]% over the past two years.
ISTAT is Italy's national statistics institute — authoritative source
Il mio affitto è aumentato del 20% e il mio stipendio no.
My rent has increased by 20% and my salary has not.
Concrete personal example; more relatable
Chiedo almeno un allineamento al tasso d'inflazione.
I am asking for at least an alignment to the inflation rate.
Minimal ask; hard to refuse outright
ISTAT (Istituto Nazionale di Statistica) is Italy's official statistics agency. Its inflation data ('NIC' index) is used to adjust public sector wages and CCNL minimum salaries. Citing ISTAT figures gives your argument official credibility.