In emphatic sentences the subject of the sentence is not stated it is implied.
eg Sit down. Be quiet. The subject is you. ie You sit down. You be quiet
The form of the verb is the base form so for cost the form is cost. But it would be hard to write an emphatic sentence for cost.
Another way of showing emphasis is to use - do + base verb
I do help!
He dideat it
straight after breakfast..
The root word of "emphatic" is "emphasia," which comes from the Greek word "emphatikos," meaning "emphatic" or "pronounced."
Emphatic is not a noun, it is an adjective, a word that describes a noun; for example an emphatic warning, an emphatic statement.The noun form is emphasis.
The past emphatic tense is used to emphasize the action or event that took place in the past. It is formed by using the auxiliary verb "did" followed by the base form of the main verb. For example, "I did complete my homework" emphasizes that the homework was definitely completed.
What is Present emphatic for the word Run?
The emphatic forms of a verb are often used to give greater emphasis to the idea express by the verb. The auxiliaries do, does and did are used to give this additional emphasis. The emphatic forms are used in only two tenses, the present tense and the past tense.
The lawyer was very emphatic when explaining the law to his client.
No, costed is not a real word, the past tense of cost is just cost.
When he spoke, Jim was emphatic about his love of minnows.
Does he run fast? is one example. Emphatic forms usually don't have subjects. The subject is implied 'you'. Come here! Come in sit down. Stop the noise. Don't be late! These are all present tense.
The past tense is also cost. It's an irregular verb.