1. Complete Sentences. Try to use complete sentences. Avoid using a "telegraphic" or "outline" style with colons (:). Colons are used much less frequently in English than in German.
avoid: Some reasons for not going: no money, no car.
better: Some reasons for not going are that we do not have any money and we do not have a car.
A complete English sentence statement (Aussagesatz) normally has a subject and a predicate. In the following sentence. The old man is the subject, and likes to eat cheese is the predicate.
The old man likes to eat cheese
In the next example, the group of words is not a sentence because the subject is missing. To correct it, add it before the verb. (Also see sentence fragments below.)
avoid: First, has always meant providing your family with a decent standard of living.
better: First, it has always meant providing your family with a decent standard of living.
2. Subject-Verb Word Order. In English statements, the subject will generally come before the verb—even if a prepositional phrase comes first!
avoid: In America drives nearly everyone a car to work.
better: In America nearly everyone drives a car to work.
3. Subject-Verb Agreement. Always double check to make sure that the verb agrees with the subject. Usually, the first verb of the main verb phrase will end with an "s" only when the subject is third person and singular (exceptions include such helping verbs as could, can, had, should, etc.)
avoid: The pencils in the box has been used before.
better: The pencils in the box have been used before.
4. Existence. Many learners of English will leave out a subject when they want to state the existence of something. In English, the most common way of expressing existence is simply with "there is". Use of the verb to exist is rather uncommon in English. One can say, "God exists" or "How long has the Universe existed?" but "There exist many approaches to this problem" sounds quite strange.
avoid: In Hawaii are lots of pineapple trees.
avoid: In Hawaii lots of pineapple trees exist.
better: In Hawaii there are lots of pineapple trees.
5. Tense. Check your work for possible problems with tense. In the following example, the adverb usually indicates that the actions are habitual, therefore, the present tense is used for both verbs (present and past tense are usually not mixed like this).
avoid: The visitor usually begin his or her stay in a hotel and met sympathetic and gracious nationals.
better: The visitor usually begins his or her slay in a hold and meets sympathetic and gracious nationals, nationals
In the following sentence, the time word after takes either present or present perfect. The verb should be either learns or has learned
avoid: After a person is learning the language, he or she begins to feel more comfortable
better: After a person has learned the language, he or she begins to feel more comfortable.
6. Pronoun Reference. A pronoun should agree with the word or words it refers to. In the following sentence, the pronoun refers to an inanimate noun -world The correct form is it.
avoid: The greenhouse effect will have a dramatic effect on the world as we know him.
better: The greenhouse effect will have a dramatic effect on the world as we know it.
7. Run-on Sentences. A frequent error is writing run-on sentences. This involves writing two sentences as one and frequently occurs when the idea in both sentences are closely related. Many students make this mistake by simply linking two complete sentences with a comma.
avoid: Abraham Lincoln is remembered for his sense of humor, John Kennedy is too.
better: Abraham Lincoln is remembered for his sense of humor, and John Kennedy is too.
8. Sentence Fragments. A sentence fragment is a group of words which ends with a period but is not really a sentence, because it is missing either a subject or a predicate. The following group of words is not a sentence, because there is no verb to go with wrist watch, It is simply a noun followed by a long adjective clause.
avoid: A wrist watch, which is a mechanical device used for telling time and is attached to the wrist.
To correct it, put a comma after time, and remove the and, thus making is attached the main verb:
better: A wristwatch, which is a mechanical device used for telling lime, is attached to the wrist.
You can create a fragment out of a complete sentence by adding certain connectives or transitional words, such as although or since.
avoid: Although the old man likes to eat cheese.
better: Although the old man likes to eat cheese, he never does.