Copula

The copula IS a very useful verb. The copula links a subject with a predicate. Therefore, the copula is sometimes called a "linking verb".

To help understand the copula, think of it as an equal sign.

Types of Sentences
Sentences with the Copula do not have to follow the Subject-Verb-Object form of a sentence. Here are some examples:

Forms of the Copula
In the examples above, we used the word "is", but the copula changes to give the listener more grammatical information. The dictionary form of the copula is the infinitive form: to be

The future tense is very easy. For 1st, 2nd and 3rd person, you always use will be: "I/you/they/we/he/it/she will be in Japan."

Plurals are also easy: The forms of the copula are the same for each tense in the plural. So in the past tense, we use "were" all the time; for present tense we use "are" all the time, etc.

Singular

Singular is a little more irregular.

The singular "you" and the plural "you" sound the same. Maybe that is why the singular forms "were" and "are" are the same in the singular and plural forms.