IELTS Advice: 'Difficult' words and how to learn vocabulary

Here's a useful question from one of our student who asked about "difficult" words and how to learn new vocabulary:

Hi Sir. Reading your blog and your study material, I’ve noticed your English is perfect, but you don’t use difficult words. Also, regarding the process of learning new words, some teachers say that we should write them on cards and write the adjective, noun, verb associated with the new word. Do you think this is a good idea?

Here's my answer:

I don't believe in the idea of a "difficult word" - any individual word can be learn't easily. What is difficult is using words together in phrases. So, I tell my students not to write down individual words, but to investigate how words work in real contexts. Instead of writing single words on cards, I'd write phrases or even sentences in a notebook. It's definitely a good idea to look for associated nouns, verbs and adjectives, but always try to find examples of how those words are used (just search for them on the Internet). Remember: it's easy to understand a word, but it's not so easy to use it in a range of full sentence contexts.