In this article, we present an example of learning based on grammar rules. Then we explain why we think this way of learning is much less effective than input-based learning. Example of learning by grammar rules
Here is an excerpt from a modern ESL textbook ("Workout Advanced" by Paul Radley and Kathy Burke, published by Nelson English Language Teaching). The textbook was used in an English class Tom attended at a language school in England.
Unit 4. Grammar: Adjectives
When two or more adjectives are used before a noun, the adjectives follow a certain order:
opinion adjectives: general/specific
descriptive adjectives: size/age/shape/colour/nationality/material
Example: They bought a lovely, stylish, large, old, rectangular, brown, English oak table.
Unit 4. Practice (next page)
Use the adjectives in the correct order before each noun to make noun phrases.
Example:
beach — white, sandy, soft --> a soft, white, sandy beach
hotel — modern, large, expensive
climate — sunny, warm, Mediterranean
water — blue, clear, clean
restaurant — international, open-air, clean
rooms — spacious, comfortable, twin-bedded
The textbook presents a grammar rule for ordering adjectives ("size/age/shape/colour/nationality/material"). Then it gives only two examples. After that, you are expected to do an exercise.
Obviously, you cannot do the exercise using your intuition (what intuition can you get from seeing only two examples?). The textbook wants you to use the grammar rule. You are supposed to classify the adjectives into one of the groups ("size", "age", etc.), and then put them in order according to the rule. In other words, you are supposed to:
recall the rule ("size - age - shape - color - nationality - material")
for every adjective, answer the question "Is it an adjective of size, age, shape, color, nationality, or material?"
order the adjectives according to the rule
Now imagine doing all these things whenever you're writing or saying a sentence with 2 or more adjectives. Can you guess how much time it would take you to build the sentence?
Is there another way? Yes, there is. You can learn by input. You can read a lot of sentences with adjectives and get a natural, intuitive knowledge of adjective order. Instead of memorizing the rule and using it to build sentences, you can get correct sentences into your head and your brain will imitate them. The "input way" is easier and it lets you speak and write faster. Of course, learning by input is not effortless. You have to spend a lot of time reading and listening to English. However, if you learn e.g. by reading a book that you like, it can give you pleasure and motivation.