Definition of Subject, Verb, Object, Modifier

Subject is part of the clause that marks what was said by the speaker. Part clauses other than the subject is the predicate. Subject is not always the same as the actor or actors, especially in passive sentences

Verb (verb) is a function word to indicate the action of the subject, showing events or circumstances. Verb is one of the eight parts of speech.

Object has two characteristics that attribute (State) and Behavior. Attribute (State) is the identity or the object itself or the information referred to also as a variable, while Behavior is behavior or what can be done by the object or also called as a method.

Modifier is a word, phrase, and clause that functions as an adjective or adverb that describes another word or group of words.

Example :  1.To make lemonade, you first need some lemons.
                2. When he arrives, we can try to build a fort.
                3. As the cat watched, the two puppies fought over a bone.
                4. The small dog was reluctant to learn new things.
                5. Walking on the ice, she slipped and fell.


Subject-verb agreement just means using the right version of the verb to agree with the subject If you use the term "verb conjugation," your mates will probably think you're bit of brainbox, but it just means "how verbs change to agree with their subjects."

It's really simple. If you're a native English speaker, you'll naturally ensure your verbs agree with their subjects
 
  Example :         1. My dog always growls at the postal carrier.

                    2. Basketballs roll across the floor.

                    3. I don’t understand the assignment.

                    4. These clothes are too small for me.

     5. katy doesn’t like vegetables.