grammar – n. the set of rules that explain how words are used in a language

subway – n. a system of underground trains in a city

mission – n. a task that you consider to be a very important duty

confused – adj. unable to understand or think clearly

linguist – n. a person who studies the way languages work

consistent – adj. continuing to happen or develop in the same way

comma – n. a punctuation mark that is used to separate words or groups of words in a sentence

chat – n. a light and friendly conversation

literature – n. written works (such as poems, plays, and novels) that are considered to be very good and to have lasting importance

refreshing – adj. pleasantly new, different or interesting