In Norwegian grammar, the Perfect Progressive Theory refers to the construction of a verb tense that combines elements of both the perfect and progressive tenses. This tense is used to describe an action that started in the past and is still ongoing or has just been completed.

To form the Perfect Progressive tense in Norwegian, we use the auxiliary verb “har” (have) or “har vært” (have been), followed by the main verb in the past participle form, and then the present participle form of the verb “å være” (to be). For example, “Jeg har spist” (I have eaten) or “Han har vært lekser” (He has been doing homework).

The Perfect Progressive tense is often used to express the duration of an action or a temporary state. It is commonly used when talking about actions that have just happened or actions that have a connection to the present. For example, “Jeg har vært i Norge i fem år” (I have been in Norway for five years) or “Vi har ventet i en time” (We have been waiting for an hour).

By using the Perfect Progressive tense, we can add more depth and detail to our sentences, making them more precise and accurate.