When asked for a word meaning “a morally or legally bound act for a person”, or “a duty or commitment”, one would probably mention the word “obligation”. And they would be right.

However, when asked about the verb form of the noun “obligation”, this is where we start to hear multiple answers. While I tend to use the verbs “to oblige” and “to be obliged”, every now and then, I would hear people mentioning the verbs “to obligate” and “to be obligated”. Even as a native English speaker, this phenomenon is pretty bizarre to me. So what gives? And is there now one correct form, or two?

To start off, the verb form conventionally considered to be correct is indeed “to oblige”, and so for just about every single context, you would be considered grammatically correct if you use the verb “to oblige”. But the verb “to obligate” seems to have entered use through American English, due to its almost complete absence in formal British English. In informal British English however, these verbs seem to be used interchangeably. But the truth is more than what it seems.

What is interesting about the difference in usage between “oblige” and “obligate” is the rise of different connotations and contexts each verb could be used appropriately. A site which seems to cover American English called Writing Explained mentioned that:

• Obliged has a similar meaning to grateful, and also carries a connotation of action without expectation of returning the favour.
• Obligated carries legal and moral aspects in addition to what “obliged” means. These legal and moral stuff are not always implied in the verb to oblige.

In a sense, the verb to obligate has become a sort-of synonym for the verb to require, as an action expected of a person. This carries a binding connotation, and hence the “legal” aspects that are carried by using the verb to obligate. Thus, the verb to obligate has a more specific context to use compared to the verb to oblige. Consider the following sentence:

• A landlord is obligated to perform necessary repairs on properties rented out to tenants.

Here, we see a situation which explicitly carries some legal connotations, stating that the necessary repairs are a legal responsibility that is required of a landlord. Thus, the use of the verb to obligate is appropriate. However, the verb to oblige could also be used here, as it covers more general contexts that may or may not entail legal or moral aspects. So here, the two verbs could actually be used interchangeably.

But now, consider the following. While it sounds old-fashioned, it still is used in some more formal contexts:

• If you could put down your weapons and speak like civilized men in this establishment, I would be much obliged.

In this context, the speaker is expressing a form of gratefulness or appreciation if the listener complies with the action required of them. No legal or moral connotations are technically carried here, and so, the verb to obligate would not be appropriate, and only the verb to oblige could be used.

So if in doubt of which verb to use, bear in mind that the verb to oblige could be used in much more contexts, while the verb to obligate has a slightly more specific usage. If you want to stay safe, use the verb to oblige; it is acceptable in more situations.