This lesson has been designed to address the problems that students have when using indefinite articles. Mandarin Chinese doesn't require the use of articles (as such) and as a result this is one of the most basic common grammar mistakes that I encounter in Taiwan.
The teacher can explain this concept during the 'activate' phase of the lesson using the slide shown to the left. 他是學生 = He is student.
Allow the students to make the mistake of saying the sentence without the article and then explain that in English we use an article 'a' when there is only one of something.
Using the same idea, allow the students to make the mistake of saying 'He is a artist' by using the slide to the left. The teacher can then explain / review the rule regarding the use of 'an' before a vowel.
It is worth noting that some very weak students will not know what a vowel is and so this will also need to be reviewed during the process in order for them to fully understand and begin to apply the rule.
The dominoes game will allow the students to work in small groups and practice saying the learned sentence pattern in a mechanical way. Students are simply required to substitute the job word and apply the correct a/an grammar rule when saying the sentence. To ensure that the students are applying the rule correctly, they are required to place a small token onto the cards as they say the sentence. It will be very apparent to the teacher which students have not understood the rule as they will struggle placing the correct a/an token. Intervention can then be given and allow the student to make the necessary progress.
The last ten minutes of the lesson can be used to allow the students to show that they have understood the lesson and can successfully apply the a/an rule. Still in their groups of four, the students are given a set of eight cards. They each choose two cards (the cards are designed to ensure that each student will have 1 x 'a' job and 1 x 'an' job). They then record a short movie simply introducing themselves and saying two sentences.
"My name is Ian. She is a cook. He is an artist."
As a final assessment I display a PPT slide that displays some jobs that they most likely don't know (architect, businessman, optician). The students write the three sentences inserting the correct article in the process.
This allows the teacher to differentiate between which students genuinely still don't know the grammar rule, and which students simply forgot to apply the rule during the speaking assessment.