A copula is a word that links the subject of a sentence with a predicate (a subject complement). In English, the copula is the verb "to be" (for example, the word "is" in the sentence "The sky is blue.")
Most languages have one main copula, but some, such as Spanish and some other Romance languages, have more than one. This is because the verb or verbs meaning "to be" in the Romance languages are derived from not just one but three Latin verbs:
As the Romance languages developed over time, the three separate Latin verbs became just one or two verbs in the Romance languages.
Oh, yeah
Alright
Somebody's Heine' is crowdin' my icebox
Somebody's cold one is givin' me chills
Guess I'll just close my eyes
Oh yeah, all right, feels good inside
Flip on the tele'
Wrestle with Jimmy
Something is bubbling behind my back
The bottle is ready to blow
Say it ain't so
Your drug is a heart-breaker
Say it ain't so
My love is a life-taker
I can't confront you, I never could do
That which might hurt you so try and be cool
When I say, "This way is a water slide away from me
That takes you further every day, hey, so be cool"
Say it ain't so
Your drug is a heart-breaker
Say it ain't so
My love is a life-taker
Dear Daddy, I write you, in spite of years of silence
You've cleaned up, found Jesus, things are good or so I hear
This bottle of Steven's awakens ancient feelings
Like father, step-father, the son is drowning in the flood
Yeah, yeah yeah, yeah yeah
Say it ain't so
Your drug is a heart-breaker
Say it ain't so