Sometimes you can look at a word and guess its part of speech. For example, if a word ends in -tion or -ation, it is probably a noun.

• Ex: (a) The teacher’s selection of questions is usually good.
• Ex: (b) The action of the police was very rapid.
• Ex: (c) The teacher will give us an examination

If you want to use these three words as verbs instead of nouns, you must change the word form. The verb forms are select, act, and examine.

• Incorrect:  (d) The teacher selections good questions.
• Correct: (e) The teacher selects good questions.

Why is (d) wrong? Why is (e) correct?

The answer is that you must use a verb form, not a noun form.

Here are four examples of useful word formation patterns:

• verb + -(a)tion -> noun       select -> selection
• verb + -able -> adjective      chew -> chewable
• verb + -ment -> noun announce -> announcement
• adjective + -ly adverb slow slowly

Learn English Grammar: Lesson 9,10 – Noun Basics, Count Nouns