Exchange dictionary

Note: This page will be regularly updated.

American English differs from the English language you've been taught at school. There is a big likelihood that you'll find yourself confused having found that a word or phrase you know and understand turns out to mean something different than what you expect.

Everyday conversation phrases and expressions:

How are you doing? - a typical question that directly follows a 'hello' and means the same as the simpler 'How are you?' The 'doing' part makes a lot of foreigners confused when they hear it for the first time. A typical response for such a question is 'Good, how are you?' - unless, of course, you feel like saying something more about yourself. It's a typical greeting that Americans exchange on an everyday basis.
Tired - to be tired does not necessarily mean 'I feel exhausted after a long day,' but rather 'I didn't get enough sleep' - what you might probably express with 'being sleepy.' Of course Americans will understand you just as well, it's just a slight tendency of the word's usage.

Time - Americans don't use phrases such as "quarter past [...]", "half to [...]", instead they say exactly what the clock reads, for example "five thirty" or "eight forty five".

Vocabulary:
(as I said, Americans will understand you if you use the words you know; my goal is to point out the words that Americans are more likely to use to name particular objects)

Car = Truck (not always, but quite often, when it comes to pick-ups which are popular in the U.S.)
Cooker = Stove
Fridge = Refrigerator. Don't ask me why Americans prefer to use words that are longer :P
Sofa = Couch
Shop, store = Grocery store
Shopping center = Mall

School (education):

Class - this one has couple different meanings, most significant being the level of education you represent depending on your age, in the United States usually described with the expected year of graduation. For example, if you are going to graduate in 2016 (as it was in my case), I belong to the class of 2016, shortly: the class of '16. Another meanings of the word 'class' are: 'subject' (so for example math, science, English etc.) and 'lesson' (understood as the time and place you're supposed to be at given time while at school. For example, 'What class are you at right now?' 'What's your next class?' 'I need to go to class.')
Course - another word for 'lesson'
Elective - elective course is a non-obligatory class (subject) you can pick as an extra to your schedule.
Grade - this one, too, has couple different meanings: the year of education you're at (so there's grades from 1st at elementary school to 12th at high school), the mark you get for your work at school (in the States it's A through F excluding E)
Passing time - a break. It's the short period of time (usually 5 or 10 minutes) between classes. Some schools also define a passing time before and after school for the students to respectively enter and leave school.
Schedule - a synonim for what we all know and love as 'timetable'. The daily/weekly chart of students' classes, bells, etc.

Tardy - another word for being late.

Freshman - 9th-grade student.
Sophomore - 10th-grade student.
Junior - 11th-grade student
Senior - 12th-grade student.

Junior High School/Senior High School - sometimes it is distinguished between the two types of high school.