1. Adhesion/adherence

Both have a common verb "to adhere" which means to stick. Adhesion is the physical condition: This paint has excellent adhesion. Adherence has the figurative sense: They are to be admired for their adherence to moral principles.

2. Admission/admittance

Admission means permission of entry. It can be physical: The admission of immigrants had to be restricted. Admittance is a formal term for right of entry. A notice that says NO ADMITTANCE on a door means KEEP OUT. Using the two words together, you could say that a drunk was refused admittance to the show even though he had paid his admission.

3. To affect/to effect

These two verbs are often mis-spelled, also in English-speaking countries. The reason may be that they have a common noun: effect. To affect means have an influence on something: The strong wind affected the tennis game. To effect means cause, bring about: The new manager effected an improvement in the EDP Department. The adjective affected can also mean the same as in many other languages: displaying mannerisms that are not natural.

4. Amiable/amicable

Although your Latin may be rusty these days, you probably still recognize that these two words must have something to do with friend. Amiable is always applied to people who are pleasant, easy-going, likeable. Amicable cannot be applied to people, only to relationships that are friendly. Using both words in one sentence, you could comment: The two amiable proprietors had an amicable business relationship for many years.

5. Beside/besides

Beside refers to the physical situation, it means side by side, close to: He sat beside her. Still in a sense physical, but used figuratively are: Beside the point, meaning irrelevant, and the slightly old-fashioned expression: He was beside himself with rage, which indicates a really boiling temper. Besides is used in two ways: as an adverb in the sense of moreover, in addition: He has not improved; and besides, he does not seem to care . Less frequently, it can also be a preposition, meaning apart from: Besides curtains, they also sell sun blinds.

6. Blink/wink

Both have something to do with the movement of the eyelids. Blink is what you do involuntarily every few seconds with both eyelids. A wink is the lowering of one eyelid to give a signal. Here is the difference, shown in artistic form in its three stages: Not quite logically, wink (not blink) is used in phrases connected with sleep: I didn't sleep a wink last night = got no sleep at all. They had forty winks after lunch= a brief sleep, a nap.

7. Blush/flush

When you are temporarily red in the face, it can be the result of either blush or flush. Emotion (embarrassment or shyness) makes you blush: When he complimented her on her first-class work, she blushed. Physical exertion causes you to be flushed: She was flushed after running for the last bus. An in-between situation can exist when you are red in the face because of a mixture of emotion and physical causes. You can, for example, be flushed with excitement.

8. Childish/childlike

Childish is no compliment. It means immature: His reaction to their mild letter of complaint was very childish. (He sulked for months.) Childlike can be a compliment, as its meaning of like a child refers to positive attributes such as innocence, grace, honesty, etc.: The movements of the dancers had a childlike grace.