1
They refer to things that are true, that have happened or that are very likely to happen.
2
are used to speculate about what might happen, what may have happened and what we would like to happen.
3
Express agreement or approval. It's a formal way of saying "Yes."
4
the state of something, especially with regard to its appearance, quality, or working order.
5
To express habits and routines, general facts, repeated actions or situations, emotions and permanent desires.
6
Is the basic unit of grammar. Typically is made up of a subject (s) (a noun phrase) and a verb phrase (v).
7
refers to a time after the current and expresses facts or certainties. In this case, there is no place for attitude.
8
It is one of the most important features of many languages, including PHP. Allows the conditional execution of code fragments. PHP has an if structure that is similar to that of C.