The Grammatical Concepts:
Morpheme:
The smallest meaningful unit of language that cannot be broken into smaller parts. A word can be composed of one or more morphemes (girl: 1 morpheme; girls: 2 morphemes).
Types of Morphemes:
Parts of speech:
The building blocks of the English sentence. They are of nine kinds: nouns, verbs, pronouns, adjectives, adverbs, prepositions, articles, conjunctions, and interjections.
Phrase:
A group of words that stand together as a single unit, typically as a part of a clause or a sentence. It cannot convey a complete thought.
Clause:
A group of words that makes a statement about someone or something. It may stand by itself to express a complete thought (Independent clause), or it may depend on some additional words to complete its meaning (Dependent Clause).
Sentence:
A group of related words that expresses a complete thought needing no other words to complete its meaning. It has (at least) one subject and a predicate (Bill plays football very well).
References:
http://www.isshm.rnu.tn/imgsite/cours/Sentence%20ElementsPFD.pdf