There is an increasing trend of old people living longer in many countries around the world. Do you think this has a positive or a negative effect on the population as a whole?
Task response measures how well you respond to the question. The example question is asking for your opinion, therefore you MUST - not should - mention your belief in the introduction paragraph, & explain your opinion with supporting ideas and logic in the body paragraphs.
Give at least 2 relevant examples in your essay. For example, to explain how older people can be a pressure to the public funding, you may say "As a major portion of Canadian population is aging, the Canadian government has to keep its notable funding aside to serve these people via medical facility, affordable transportation and so on."
Lets check what is wrong with the following Introduction paragraph. The Task 2 is asking "Do you think this has ...". So, you MUST state your opinion in the introduction, failing to do so will hurt you miserably.
Coherence = logical and consistent, nice organization
Cohesion = bond (e.g. In addition, but, By contrast, For example, To conclude)
A proper paragraphing is vital to make a Writing TASK coherent. You should write 4-5 paragraphs, ideally four. For the sample question, you may write 4 paragraphs i.e. (1) introduction (2) body paragraph 1 (3) body paragraph 2 (4) conclusion. The skeleton can be as follows:
Introduction: paraphrase the question's statement. thesis outline (I think negative impact)
Body Paragraph 1: Logic 1 on why you think more aging population has negative impact. Explain your logic. Give example.
Body Paragraph 2: Logic 2 on why you think more aging population has negative impact. Explain your logic. Give example.
Conclusion: restate your point of view.
All the RED words in the following example contributes to the clear rendition of COHESION.
Vocabulary contributes to the marking criteria by 25% in IELTS Writing and Speaking. Please note that vocabulary does not mean only the abstruse academic words. In other word, you may simply use different combination of words or collocation. For instance, instead of writing food in a sample TASK 2, you may say food choice, the available option of food. Both of these 2 words shows your level of vocabulary.
Learn some synonyms and academic versions of common words regardless. For example:
Do => Perform
show => Depict (a common word for TASK 1 in Academic writing), rendition - a noun form of show. Let's learn some vocabularies from the following video.
If you already have forgot today's TASK 2, here it is: "There is an increasing trend of old people living longer in many countries around the world. Do you think this has a positive or a negative effect on the population as a whole?
The entire 1st sentence can be expressed by a single word - Longevity.
I strongly recommend (recommend is a high-level vocabulary of the word "suggest") you to learn at least 200 IELTS Writing vocabulary (Topic related). I have prepared a list for you as follows;
Grammatical Range & Accuracy
Unluckily the most ignored marking criteria: grammar. Wait. It's not Grammar but Grammatical Range & Accuracy. This means only writing grammatically correct sentences won't be enough. If you write won't in your writing, you will get a lower mark in the Grammar criterion as won't is NOT formal.
You need to write grammatically accurate sentences (Grammatical Accuracy)
You have to write in a range of sentence structures in a flexible way (Grammatical Range).
To get a Band of 7 or higher, you should use complex & compound sentences in your writing flexibly. Learn those from 1. Collins Grammar for IELTS, 2. ieltsbuddy.com/grammar 3. Any other source you like.
By the time Writing module will appear in your IELTS exam, you brain will be exhausted already. But, don't forget that a Writing score less than 7 can cost you an arm and a leg . Anyway, you have already figured out that IELTS Writing has 4 marking criteria: Task Response, Coherence & Cohesion, Lexical Resource, Grammatical Range & Accuracy.
 In our IELTS Writing examination, we will NEVER write "exam". Always write words in full form: Examination, do not (not Don't).
 Cost you an arm and a leg: a popular idiom. You are welcome to utilize this type of idioms in your IELTS Speaking exam. NEVER use idioms in IELTS Writing. Except some acceptable phrasal verbs, you should NOT use phrasal verbs in Writing as well. If you use phrasal verbs in Speaking, you will be higher mark unlike in Writing where you will be penalized.
Pursing Ph.D. at Dalhousie University, Canada
IELTS Trainer at HigherStudyAbroad