Introducing a new grammatical topic, such as the use of "a" and "an" as an indefinite article, requires the teacher to explain the rules that govern their use. However, saying only that "a" goes before words beginning with a vowel and "an" before words beginning with a consonant is insufficient, as children will tend to write "a honorable person" afterwards. Presenting the exceptions along with the rule gives students a complete picture of the topic and prevents wrong use of grammar from becoming the norm.
Words with irregular inflection, such as irregular verbs and nouns with distinctive plural formation, don't adhere to specific rules. For instance, teachers cannot explain why drive becomes drove or why the plural of mouse is mice. However, they can help students by stressing wrong inflection cases, so that students can become instantly alerted when they come across them. For example, teachers can write "mouse" and "mice" on the board with a blue marker and add "mouses" with a red marker next to them, as a way of visualizing the correct and wrong plural formation.
A difficult issue for young children is to recognize irregularly pronounced words: words that sound differently than their spelling suggests. An examples of such a word is "beautiful," which when sounded out is "bee-ou-tifu" rather than "be-a-ou-tiful." A method to introduce such words to students is to include them in passages during reading practice. When students come across the word and pronounce it incorrectly, stop the exercise and explain the correct pronunciation to students.
The teacher must prepare a set of flashcards -- one for every student -- that contain the correct inflection of irregular words and another set with the wrong inflection of the same words. Also, she must create a set of irregularly pronounced words and of definite and indefinite articles. During the lesson, the teacher narrates a short story, and pauses when irregular words appear. For irregularly pronounced words, the teacher must say the word aloud and ask the children to spot it on their flashcards deck, while for words with irregular inflection, the teacher must describe "more than one mouse" for instance and let children find the "correct inflection" card.