The concept expressed in English by the verb "to be" is expressed in Haitian Creole by two words, se and ye.

The verb se (pronounced "say") is used to link a subject with a predicate nominative:

Haitian Creole English
Li se frè mwen he is my brother
Mwen se yon doktè I am a doctor
Sa se yon pye mango That is a mango tree
Nou se zanmi we are friends

The subject sa or li can sometimes be omitted with se:

Haitian Creole English
Se yon bon ide That is a good idea
Se nouvo chemiz mwen This is my new shirt

For the future tense, such as "I want to be", usually vin "to become" is used instead of se.

Haitian Creole English
L ap vin bòfrè m He will be my brother-in-law
Mwen vle vin yon doktè I want to become a doctor
Sa ap vin yon pye mango That will become a mango tree
N ap vin zanmi We will be friends

"Ye" (pronounced "yay") also means "to be", but is placed exclusively at the end of the sentence, after the predicate and the subject (in that order). This happens especially with question words:

Haitian Creole English
"Ayisyen mwen ye" = "Mwen se Ayisyen" I am Haitian
Ki moun sa ye? Who is that?
Kijan ou ye? How are you?

The verb "to be" is not overt when followed by an adjective or prepositional phrase, that is, Haitian Creole has stative verbs. So, malad means "sick" and "to be sick":

Haitian Creole English
M gen yon zanmi malad I have a sick friend.
Zanmi mwen malad. My friend is sick.
Ou nan kay la. You are in the house.