My 3 main grammar mistakes

I always make careless grammatical mistakes in my English essay and I need to improve on it. Basically I made a lot of mistakes on the following grammar points: WW (wrong word), SVA (subject-verb agreement), and art (article).
For WW, I have made plenty of mistakes in my writing assignment 1 and 2. For example: an electric car is rechargeable and it emits lesser greenhouse gases. In this case, the ‘lesser’ is a wrong word and it should be replaced by ‘less’. An example from writing assignment 2: research must be carried on and specialists are required to be skillfully trained. In this case, the word ‘carried on’ should be ‘carried out’ which is more appropriate in this situation.
Then, for SVA, I am confused about the grammar form sometimes but I am trying to avoid such mistakes. Example: it is a fact that cars with lighter weight consumes less energy. In this case, the ‘consumes’ should be ‘consume’ because ‘cars’ is a plural subject. Another example: the adoption of green chemistry eliminates toxic waste and thus cut down the corresponding enormous cleaning cost. In this case, the ‘cut’ should be ‘cuts’ because ‘green chemistry’ is a singular subject.
Next, for the article point, I always have problem in defining the type of an article, either general article or specific article. For example: a high speed car needs longer charging period for the battery. And the correct answer should be: a high speed car needs a longer charging period for the battery. An example from writing assignment 2: the main idea of the green chemistry is to provide solutions to the global challenges such as global warming, and to enjoy an increased standard of living without imposing negative effect on the environment. There are 3 article errors in the sentences, where the ‘the’ in front of ‘green chemistry’ and ‘global challenges’ must be omitted and an ‘a’ is necessary in front of ‘negative effect’.
In conclusion, I will work on the English grammar in order to produce a good essay.