Ielts guides

Lexical Resource
Your lexical resource concerns your ability to effectively tap into your "mental dictionary" or lexicon. If you tend to speak with an expansive, varied vocabulary, you will surely do well in the lexical resource category. Note that both the appropriateness and accuracy of your vocabulary choices are considered here, so you must be sure to choose the correct word for both its meaning AND the context in which it appears.
On the other hand, if you have a limited vocabulary, or are inexperienced with finding the right context for some words, you may need some additional practice in this area. Remember, just knowing what an English word "means" does not ensure that you are using it correctly, as English words often have connotations which are not necessarily found in the dictionary. By the way, you'll understand what we're talking about more as you go through our IELTS speaking samples. Continuing on, repeating the same words that you are comfortable using again and again is another common mistake to avoid, as it will indicate to the examiner that your lexical resources are limited. Finally, the examiner will expect you to be able to correctly paraphrase IELTS speaking questions by using your own words to repeat the question. That means listening and understanding the phrasing of questions is important, too.
Grammatical Range
Unsurprisingly to most, your grammar will also be considered as part of your IELTS speaking score. To do your best in this category, you should become familiar with as many IELTS speaking topics as you can, so you can focus more on your grammar, then you can attempt to demonstrate your grammatical ability and range as naturally as possible. Avoiding mistakes will not be enough to get a high score in this area, as the examiner needs ample opportunities to hear you using more complex or difficult grammatical structures and features. Your goal should be to show off your grammatical knowledge while appearing comfortable using a variety of sentence constructions and verb tenses.
However, as many second-language speakers know, this is easier said than done. If you're confused about how to use some grammar points, or you aren't sure whether you're making mistakes when speaking, consider recording your spoken responses next time you practice answering IELTS speaking test questions. While listening, you may find that there are some mistakes you didn't even know you were making. Discovering these will allow you to figure out how to break bad habits BEFORE the examiner hears you making them on the test. If possible, get a native speaker, instructor, or a friend with good English to help you correct your mistakes and explain grammar rules. Be sure to go back and review as well - even the most basic grammar lessons.