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.
"Would you like to have lunch with me?" is fine. You might want to preface it with a question, such as "Do you have any plans for lunch today?" If they reply "No" then you can extend the invitation. If they have a previous engagement, you can re-word your invitation to "Would you like to have lunch with me sometime this week?" or something similar.
What are the most appropriate formulae..? 
Linear Mode
