Here's a breakdown of the sentence and its meaning:
* Watashi (私): Means "I"
* WA (は): A particle used for emphasis, similar to "is" or "am" in English.
* Isuru (する): A verb meaning "to do"
* Desu (です): A polite form of "to be" or "am"
Putting it all together, "Watashi WA isuru desu" means "I am doing" or "I do."
However, this sentence is quite formal and not commonly used in casual conversation.
A more natural way to say "I am doing" in Japanese would be:
* Watashi wa [action verb] desu. (For example, "Watashi wa taberu desu," meaning "I am eating.")
* Watashi wa [action verb] te iru. (For example, "Watashi wa taberu te iru," meaning "I am eating.")
Remember, the specific verb used will change the meaning of the sentence.