Active sentences in the present continuous tense have the following structure:
Subject + is/are/am + -ing form of the verb + object
Passive sentences in the present continuous tense have the following structure:
Object of the active sentence + is/are/am + being + past participle form of the verb + by + subject of the active sentence.

Simple Present tense

An Active sentence in the simple present tense has the following structure:
Subject + first form of the verb + object

Incorrect: He said to me to go.
Correct: He told me to go.
Incorrect: She said to me that she would be late.
Correct: She told me that she would be late.

Sentences which express request, order, advice, suggestion, prohibition etc., are called imperative sentences.

Incorrect: Each of these girls sing well.
Correct: Each of these girls sings well.
Incorrect: None of my student attended the class today.
Correct: None of my students attended the class today.
Incorrect: One of my servant has gone on leave.
Correct: One of my servants has gone on leave.
Incorrect: Some of my servants has gone on leave.
Correct: Some of my servants have gone on leave.

Type 3 conditional (Impossible condition)

Here we use a past perfect tense in the if clause and would have + past participle in the result clause.

A conditional sentence must have at least two clauses: a conditional clause and a result clause. The conditional clause usually states a condition and the result clause states what will happen if the condition is fulfilled.