Breakdown of Lo psicologo crede di capire il problema.
il problema
the problem
capire
to understand
credere
to believe
di
to (linking a verb to a following infinitive)
Questions & Answers about Lo psicologo crede di capire il problema.
Why do we use di capire instead of che capisca here?
In Italian, when the subject of the main verb (lo psicologo crede) is the exact same as the subject of the second verb (he is the one who understands), we use di + the infinitive verb instead of che + the subjunctive. Since he believes that he himself understands, we use di capire.
How would this sentence change if the psychologist believed that I understand the problem?
Because the subjects would be different (he believes vs. I understand), you couldn't use the di + infinitive shortcut anymore. You would have to use che followed by the subjunctive: Lo psicologo crede che io capisca il problema.
Why does psicologo use the article lo instead of il?
Masculine singular nouns that start with ps- take the definite article lo instead of il. This rule also applies to words starting with z-, gn-, or s followed by a consonant.
Problema ends in "-a", so why does it take the masculine article il?