

Это очень простой рецепт.
This is a very simple recipe.
Ответ совсем простой.
The answer is really simple.
Это не такой простой вопрос.
It's not such a simple question.
"простой" is in the lesson "Adjectives 2" (Level 4), along with 17 other useful words. LinDuo has 180 topic lessons like this one, 2,380 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.