You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly at the top of your post. Please note, all posts are moderated by our in-house language experts, so make sure your suggestions, help, and advice house the kind of information an international language teacher would offer. If not, and your posts do not contribute to the topic in a positive way, they will be subject to deletion.
'Although travelling by bus is cheap, it is crowded.
Although travelling by bus is cheap, buses are crowded.
Although buses are crowded, they are cheap.
Although travelling by bus is cool and clean, it is cheap.'
grammar question 
Linear Mode
