this will help you to see clearly what kind of sentence you´re reading, and, after identifying it, be able to understand it, translate it, or structure your own.
type of sentence
This is the first step:
1) a question mark... (if it's there, it's a question.
2) the word NO, or NEVER (it's a negative sentence)
3) If there are none of the above, it´s an affirmative sentence
Identify the time of the action. The base form, the past tense, or the use of the modals SHALL, WILL, or GOING TO
Look at the auxiliary verb:
1) DO for simple,
2) BE for continuous or progressive, or
3) HAVE for perfect.