• A topic sentence is a complete sentence; that is, it contains at least one subject and one verb. These examples are not complete sentences because they do not contain a subject and a verb:
INCOMPLETE Communicating with colleagues
INCOMPLETE How to improve online social networks.
• A topic sentence contains two parts: a topic and a controlling idea. It names the topic and then limits the topic to a specific area to be discussed in the space of a single paragraph.
Communication with colleagues requires sensitivity and understanding.
Improving online social networks can help professionals communicate.
• A topic sentence is the most general statement in the paragraph because it gives only the topic and the controlling idea. It does not give any 'specific details.
This is a general statement that could serve as a topic sentence:
The Arabic origin of many English words is not always obvious.
This sentence is too general. It doesn't provide much guidance about what the paragraph will be about.
English has been influenced by other languages.
On the other hand, this sentence is too specific. It could serve as a supporting sentence but not as a topic sentence.
The slang expression so long (meaning "good-bye") is probably a corruption of the Arabic salaam.