2. If I ____ a word, I look it up in my dictionary. a) doesn't know b) not know c) don't know

The correct answer is c) don't know. Explanation: This sentence is a Type 0 conditional, which expresses a general truth or a habit. The correct structure is: If + present simple, present simple So, the correct sentence is: If I don't know a word, I look it up in my dictionary.