Les gouvernements sont inutiles depuis leur déclin.
(The governments has become useless since their decline)
THE VERB
The verb in this sentence is "être". Être is used like "to be" of English language. The word "sont" is present indicative third person plural of être. These are present indicative conjugations of être:
je suis
tu es
il/elle est
nous sommes
vous êtes
ils/elles sont
NOUNS
"gouvernement" means government.
"inutile" means useless.
"déclin" means decline.
PREPOSITIONS
"depuis" means since.
PRONOUNS
"leur" means their. "leur déclin" means their decline.