How to Explain a Technical Problem in Simple English

1 Example dialogue

Read the conversation. Then read it out loud. Try both parts.

Ravi, a software engineer, explains a problem to Emma, a manager who is not technical.

Emma Ravi, I heard the app was down this morning. What happened?
Ravi Yes, for about 40 minutes. Basically, too many people tried to log in at the same time, and the system couldn't handle it.
Emma Why did that happen today?
Ravi We sent a marketing email at 9 o'clock, so thousands of users opened the app at once. It's a bit like a traffic jam.
Emma I see. Was any data lost?
Ravi No, nothing was lost. The main effect was that some customers couldn't log in.
Emma OK. How do we stop it happening again?
Ravi In the short term, we've added more servers. In the long term, I'd recommend that we send big emails in smaller groups.
Emma That makes sense. Can you put that in a short email for the team?

These are the most useful phrases from the dialogue, with what they mean and when to use them.

“Basically, ...”
Signals that you will give the simple version. Very useful before a technical explanation.
“...and the system couldn't handle it.”
"Can't handle" means something is too much for a person or system.
“It's a bit like...”
Use a simple comparison (an analogy) from everyday life. It helps non-technical people understand fast.
“The main effect was that...”
Tell people what the problem means for them. Managers care about effects more than causes.
“In the short term... In the long term...”
A clear way to separate a quick fix from a real solution.
“I'd recommend that we...”
A polite, professional way to make a suggestion.

UK / US: In British English, "I'd recommend we..." (without "that") is also very common in speech.

Answer each question out loud, not in your head. Use the key phrases. If you can, record yourself on your phone and listen back.

Explain a real technical problem from your work to someone who is not technical. Use problem → cause → effect → solution.
Find an everyday comparison for a technical idea from your job. Start with "It's a bit like...".
Your manager asks, "How do we stop it happening again?" Give a short-term and a long-term answer.
Explain a delay in your project in four sentences.
Say one technical sentence from your job, then say it again in simpler English.

Many learners make these mistakes in this situation. Here is the natural version.

Not: The load balancer failed because the autoscaling policy had a misconfigured threshold.

Say: Basically, the system didn't add more capacity fast enough when lots of people logged in.

Technical words are fine with engineers. With managers and clients, explain what happened, not how the system works.
Not: It was not my fault, the marketing team sent the email.

Say: The email brought a lot of users at once, so next time we can send it in smaller groups.

Blaming people sounds defensive. Focus on the cause and the solution.
Not: The problem has happened yesterday.

Say: The problem happened yesterday.

With a finished time like "yesterday", use the past simple, not the present perfect.
Not: We need to make a fix of the bug.

Say: We need to fix the bug.

Use the simple verb. "Fix", "solve" and "repair" are all clear and natural.