Onto or On to: An Everyday Guide to Differences and Use

“Onto” is a preposition, but it isn’t an ordinary preposition. It has some very specific rules for usage.

When you use the word “onto,” it often means something has moved, is moving, or will move to a position on another surface or object. Think “upon” or “on top of.” These examples of “onto” will help:

• The cat jumped onto the counter.
• I put the hat onto my head.
• The children got onto the school bus.

Another, less common, way to use “onto” is to show understanding of a concept or awareness of a situation. In this case, it means someone is fully informed about something else, as you can see in these example sentences:

• The children were onto the magician and no longer saw his tricks as magic.
• We tried to avoid gym class by taking a long time on our math test, but the teacher was onto us.
• My mom snuck vegetables into a brownie recipe, but I was onto her when I saw the kale.

Even less commonly, “onto” can indicate a transition or continuation from one activity to another. You’ve probably used it this way in speech, but you don’t often see it in writing. However, it can come in handy when you’re writing dialogue or using a conversational tone. These examples can help you understand how to use it this way:

• This section of the test is done. Onto the next one!
• I’ll go onto the next question after I finish this one.
• I finished cleaning the sink, and now I’m onto the stove.

If you’re wondering when to use “on to” instead of “onto,” there’s a very specific scenario that requires the space between the two words. In the case of “on to,” the word “on” is actually part of the verb. This is called a phrasal verb, since it involves more than one word.

The space between the “on” and the “to” helps separate them, since they really don’t go together at all. These examples will help you understand:

• I couldn’t log on to the school wifi.
• It took me forever to catch on to the joke.
• A good driver should hold on to the steering wheel with both hands.
• After we finish math, we’ll move on to language arts.
• I am someone you can count on to get things done.

Like so many aspects of the English language, there’s a helpful cheat or grammar hack for figuring out whether you should use “onto” or “on to.” It only works for “onto” involving movement, but that covers the most common situations you’ll encounter.

Add the word “up” before the “onto.” When it works, you’ll know that “onto” is correct. When it doesn’t, you’ll know you should consider using two words. You’ll see it in action in these examples:

• Works: The dog got up onto the sofa.
• Works: I put the paper up onto the teacher’s desk.
• Doesn’t work: I held up on to the safety handle.
• Doesn’t work: After the science museum, we’ll move up on to the art museum.

While there are often subtle differences between American and British English, the rule is the same for “onto” vs. “on to.” The only distinction is that British English may have some different verbal phrases involving “on.”

For example, a British colloquial phrase for being friends with someone is to “get on” with them. This means you could encounter a use of “on to” like this: “We need to get on to get things done.”

While you can speak correctly without ever having to consider whether you are using “onto” or “on to,” you’ll need to know the difference when you’re writing. Like “affect” vs. “effect”, the words sound the same and only have subtle spelling differences. It pays to take the time to learn these common grammar mistakes so you can write clearly and confidently.