 One very common problem for English learners of every level is using the wrong word because English has a lot of words that seem very similar but they're actually used in different ways. In today's lesson I'm going to teach you 8 pairs of confusing words in English and show you how to use each one correctly with lots of examples. If you like today's lesson, check out my e-book, 100 Common Errors in English for more easy to understand explanations of confusing words and common grammatical mistakes. Enjoy today's lesson. Deny and Refuse Deny means to say something is not true or say that you did not do something. The teenager denied stealing the DVDs from the store. He said he didn't do it. Refuse means not to do something or say firmly that you will not do something. The employee was fired after he refused to do with the manager asked. Notice that after deny we always use the ing form and after refuse we always use the to form. Afraid, scared, and frightened. Even in the passive voice, after the verb to be and before of, you can use afraid or scared with no change in meaning. She's afraid of spiders. She's scared of spiders. However, when used in the active voice you can use only scared or frightened. The loud noise scared me. The loud noise frightened me. You can also describe something that causes fear as scary or frightening. It was a scary experience. It was a frightening experience. Staff and Employees Both of these words refer to people who work at a company. But staff is always singular and uncountable. It describes the entire group of workers as one thing. Employees is countable and plural. It describes the collection of individual workers. The entire staff was happy about the extra day off. All the employees were happy about the extra day off. Notice that with staff we use was and with employees we use were. Whenever you use a specific number use employees or staff members. 30 Employees Received Races 30 Staff Members Received Races Interfere and Intervene Interfere has a negative connotation. It is when someone or something affects a situation and you don't want it to. I wish my mother would stop interfering in my life. Intervene has a more positive connotation. It is when someone or something affects a situation in a good way. Bob and Joe were about to start fighting but Pam intervened and calmed them down. Problem and Trouble Problem is countable and trouble is usually uncountable. I'm having a problem with the computer. I'm having trouble with the computer. The bad internet connection caused problems for the students. We have two major problems. Don't say we have two major troubles. Trouble can also be used as a verb. These test results are troubling me. That means making me worried. Relation and Relationship Relationship can describe a connection between two people. It can be romantic or romantic. I've been dating my boyfriend for three years. We have a great relationship. He has a terrible relationship with his father. Both relationship and relation can describe connections between two things. I'm studying the relationship between education levels and poverty. There's a close relation between smoking and lung disease. The word relations, plural, is used with general connections in a specific category. Like international relations, diplomatic relations, race relations, etc. Suppose and supposed to The word suppose means something like think, believe, imagine or expect. He's not answering his cell phone. I suppose he's already gone to bed. After all, it's midnight. The expression suppose to means something should be done. But it was not or is not usually done. I was supposed to go to work today. But I'm sick so I stayed home. We're supposed to park our cars in the company garage. But most people just park on the street. Switch Switch and change The word change means for something to become different. The word switch is more specific. It means to stop using or doing one thing and start using or doing another. I'm going to change a few things in my life this year. Could you switch seats with me so that I can sit next to my husband? This means the two people will exchange seats. Her personality has changed a lot recently. I wasn't happy with my Nokia cell phone so I switched to a Samsung. This means I stopped using the Nokia and started using the Samsung. For more lessons on errors and confusing words, you can get the e-book 100 Common Errors in English, available at espressoenglish.net.