Verbal comprehension IQ tests measure your understanding of concepts in word form. The test includes vocabulary, similarities, information processing and comprehension testing. During a verbal IQ test, it is checked whether a person recalls spoken words, understands the meaning of both spoken and written information, and is capable of finding similar or different words.
Verbal fluency tests assess the ability to speak and write with ease. This ability is different from verbal comprehension in that it measures the ability to build coherent sentences and whole paragraphs (both in spoken and written form) with the use of words. It does not have to mean that a person who speaks with ease has a vast vocabulary or expert-level understanding of how the language works --- it just means that he is able to express his thoughts in a coherent and easy-to-grasp way.
Reasoning IQ tests check the ability to solve problems, learn from the experience and use the ability to solve other problems. It measures how a person comes to the solution of a given problem, how long it takes her to find the answer and whether she is able to use the knowledge again in a different context.
Spatial skills IQ tests measure the ability to distinguish shapes, sizes and spatial relationship between objects. These tests are useful assessment tools if a person is interested in becoming an architect or an interior designer, as they determine whether a person has spatial imagination and is able to see complex objects in space from all sides in his mind's eye.
Numerical skills tests measure the ability to perceive and understand numbers. They measure such basic mathematical skills as addition, subtraction, multiplication and division as well as the ability to see mistakes, spot missing numbers in a series and notice numbers that have a similar pattern. The tests also assess the capacity to understand the significance of numbers in different contexts, for example on a bill or bank statement.
Perceptual speed measures how quickly a person is able to perceive changing data, remember data for future use and make correct decisions within very short periods of time. This type of test assesses how quickly a person is able to compare letters, numbers or other data in a quickly changing environment.
Rote memory is the ability to recall things that have been learned by heart. It refers to being able to remember things such as the alphabet, multiplication tables, spelling rules or songs and poems.