"Into/In To", "Onto/On To," and "Up To"

"In To" or "Into"?

When the words "in" and "to" appear next to each other in a sentence, writers are often unsure whether to use "into" or "in to." This usually happens when the verb in the sentence includes the word "in" (e.g., hand in, step in, turn in).

More about "In To" and "Into"

Here are some example sentences with "in to":

• Paul wanted to hand the purse in to see if there was a reward.
(In this example, the verb is "hand in." It is called a phrasal verb because it is made up of two words. The word "to" is from "to see," which is the infinitive form of the verb.)
• Paul wanted to hand the purse in to the police.
(In this example, the word "to" is a preposition in its own right. It is part of the prepositional phrase "to the police.")

So, in the two examples above, the word "to" was separated from "in" because "to" had its own role to play in each sentence. In the first sentence, "to" marked "to see" as an infinitive. In the second one, "to" headed the prepositional phrase "to the police." That's quite a complicated concept if you're new to grammar, and, unfortunately, it's not the end of the story. Confusion arises with verbs like "drive in," "dive in," "put in," and "fall in " because "drive into," "dive into," "put into," and "fall into" are also valid verbs.

Example sentences with "into" and "in to":

• Put the fruit in the basket.
• Put the fruit into the basket.
• Put the fruit in to the basket.
(This is wrong because "to the basket" is not the prepositional phrase. The prepositional phrase is "into the basket.")

Here is another example:

• Dive in the water.
• Dive into the water.
• Dive in to the water.
(This is wrong because "to the water" is not the prepositional phrase. The prepositional phrase is "into the water.")
• Dive in to test the water.
(This one is correct because "to" marks the infinitive verb "to test." In other words, "to" has its own role to play in the sentence.)

"Into" Is One Word

The word "into" is a preposition. It is written as one word.

If, for some reason, "to" follows "in" in your sentence, check that "to" has its own role to play (e.g., it's there to show an infinitive verb or to head a prepositional phrase). If it does have its own role, then keep "in" and "to" separate. If it doesn't, you're looking at the preposition "into."

Of note, the use of "into" and "in to" has nothing to do with UK or US writing conventions.

"On To" or "Onto"?

The guidelines above apply equally to "onto" and "on to." As a general observation, when "to" follows "on," it usually has its own role to play. This means that "on to" is more common than "in to."

Example sentences with "onto" and "on to":

• Dive on the bed.
• Dive onto the bed.
• Dive on to the bed.
(This is wrong because "to the bed" is not the prepositional phrase. The prepositional phrase is "onto the bed.")
• Dive on to sleep for an hour.
(This one is correct because "to" marks the infinitive verb "to sleep." In other words, "to" has its own role to play in the sentence.)

• Move on to the next chapter.
(This is correct because "to the next chapter" is a prepositional phrase. As a rule, this happens more with phrasal verbs with "on" (e.g., to move on) than with phrasal verbs with "in" (e.g., to move in).)

Bear in mind that "onto" can mean "on top of." If this causes a problem, use "on to." For example:

• After checking the sheep, we moved onto the cows.
• After checking the sheep, we moved on to the cows.

"Up To" or "Upto"?

Finally, an easy rule: "Up to" is never written as one word.

Example sentences with "upto" and "up to":

• I can afford upto 400 pounds.
("Upto" is always wrong.)
• It takes up to four hours to hard boil an ostrich egg.

Is It Magic?

Be wary of the verb "to turn into" because it has two meanings. For example:

• The car turned into a garage.
(This could mean two things. Was the car transformed into a garage or did the car drive into a garage?)

To avoid ambiguity, it is normal to write:

• Turn in to to mean "drive into," "walk into," etc.
• Turn into to mean "transform into."

Example sentences with "turn into" and "turn in to":

• He turned the car in to the cul-de-sac.
(Using "into" is also acceptable. You have a choice.)
• He turned the car into gold.