Explain the concept of present tense in passive voice.

The concept of present tense in passive voice refers to the grammatical structure used to describe actions or states that are happening in the present time, but with the focus on the receiver of the action rather than the doer. In passive voice, the subject of the sentence is the receiver of the action, while the doer or agent is either not mentioned or placed after the verb.

To form the present tense in passive voice, we use the auxiliary verb "to be" in the present tense (am, is, are) followed by the past participle of the main verb. The past participle is usually formed by adding "-ed" to regular verbs, while irregular verbs have their own specific forms.

For example:
- Active voice: The chef cooks the meal.
- Passive voice: The meal is cooked by the chef.

In this example, the subject "the meal" becomes the focus of the sentence in passive voice, and the doer "the chef" is mentioned after the verb "is cooked." The verb "cooks" in active voice changes to "is cooked" in passive voice, with the auxiliary verb "is" indicating the present tense.

It is important to note that the present tense in passive voice can also be used to describe general truths or habitual actions. In these cases, the auxiliary verb "to be" is still used in the present tense, but the main verb remains in its base form.

For example:
- Active voice: They recycle paper.
- Passive voice: Paper is recycled.

In this case, the subject "paper" is the focus of the sentence in passive voice, and the doer is not mentioned. The verb "recycle" in active voice changes to "is recycled" in passive voice, with the auxiliary verb "is" indicating the present tense.

Overall, the concept of present tense in passive voice allows us to emphasize the receiver of the action rather than the doer, and it is formed by using the auxiliary verb "to be" in the present tense followed by the past participle of the main verb.