underline simple subject and simple predicate:

Ireland's highest peak is in the Mountains of Kerry.

simple subject is peak
simple predicate is "is in"

You're mostly right.

The simple predicate is just "is." "In" is a preposition beginning the phrase "in the Mountains."

To identify the simple subject and simple predicate in a sentence, you can follow these steps:

1. Identify the subject: The subject is the person, place, thing, or idea that the sentence is about. It performs the action or is described in the sentence. To find the subject, ask yourself "Who or what is the sentence talking about?" In this case, the sentence is talking about "Ireland's highest peak."

2. The subject can sometimes be complex or include additional modifiers. However, the simple subject is the main noun or pronoun that the sentence centers around. In this case, the main noun is "peak."

3. Identify the predicate: The predicate is the part of the sentence that includes the verb and provides information about the subject. To find the predicate, ask yourself "What does the subject do or what is being said about it?" In this case, the predicate is "is in the Mountains of Kerry."

4. The simple predicate is the main verb or verb phrase that relates directly to the subject. In this case, the main verb phrase is "is in."

So, in the given sentence, the simple subject is "peak" and the simple predicate is "is in."