The verb to be (for the ´is´ in English) is handled in a special way, it is different from the other verbs. This is also the case in Turkish, the use of the verb to be is very unique. Unlike all the other verbs, to be is expressed with suffixes. It can be in one of present tense or past tense. Let´s see it in present tense and past tense for different cases of personal pronouns.
For the third person of the present tense to be, there are two cases. One with no suffix and one with -dir. If you are making a personal statement or you are talking in a casual way, you use the no suffix case. However, if you want to make a definitive or informative statement like one in an encyclopedia, you use the suffix -dir. Both have the same meaning, and sometimes can be used interchangeably. Let´s see examples to this.
When constructing the third person plural past tense form of to be, the suffix -ler can be ommitted in some cases. These are explained below:
a. Humans or objects that have no individuality take singular conjugation for third person plural. But if the speaker wants to give objects individuality then he can use plural. This would be a poetic sentence.
b. Humans and other things that have individuality (for instance animals that have names) can take either singular or plural conjugation. Usually if the subject is defined (if we known them) then we use plural conjugation. If the subject is undefined then we use singular conjugation.
Since the verb to be is different for each personal pronoun, personal pronouns can be omitted in speech or writing. The meaning of person is given with this verb. To say "I am beautiful." you can use one of:
Using the personal pronoun adds the meaning of stressing person. We will use the personal pronoun in parenthesis to indicate that it is optional.
Now, let´s see where to be is used: