This is the beginning of one of the most common questions English teachers get asked. And the answer is usually, Well, it’s technically correct, but we never actually say that in English. Which in turn is usually met by frustrated sighs. For all the language’s flexibility, we often fix on only one of the many possible ways to express an idea. This is often a tremendous source of frustration for learners, especially if they’re feeling pleased about using a certain grammar form, only for their teacher to tell them what they’re saying doesn’t really sound natural.
Often, this stems from direct translation from one’s mother tongue. In French for example, it’s standard to use nouns to refer to feelings. For example:
J’ai faim. = I have hunger.
J’ai soif. = I have thirst.
J’ai peur. = I have fear.
J’ai chaud/froid. = I have heat/cold.
Of course we would never utter any of those sentences on the right, but they’re not strictly, grammatically incorrect. We can say I have a feeling, after all. But if we want to refer to a specific feeling, we have to use an adjective. Why so picky? I think it’s largely because when we listen to someone speaking in our native tongue, we tend to do it mainly on autopilot. If we had to consciously listen to every single word we hear, it’d be exhausting. So our brain absorbs the words without dwelling on them, and we know what the person is saying from our familiarity with the phrases. Our minds tend to process words in chunks, so with fairly short sentences, we tend to take it all in in one go. It’s easier then for us to use one form (I’m + adjective) for one function (referring to feelings) so it’s easier to get accustomed to that form.
Sometimes, there’s a more specific reason, like my theory that we don’t tend to use the verbs to eat and to drink very often, as they make us feel squeamish by making us picture all that food and drink sloshing around in someone’s mouth. Of course they’re two of the earliest verbs we teach students, so no wonder they get annoyed when we tell them not to use when they’ve got to a higher level.
Oftentimes, something can be grammatically correct but far too formal. This tends to be an issue mainly for speakers of Romance languages, as they’re a lot closer to Latin than English. And of course there are plenty of Latin-based words in English, but many of them have a more everyday word of Germanic origin which it would be much more natural to use. Apart from specific words, structure can be issue for speakers of these languages. It’s very common for them to say something like:
I went to the house of my friend yesterday.
I went to my friend’s house yesterday.
Of course both are grammatically correct, but a native speaker would only ever use the latter. The former sounds much too formal, but that noun + of + noun structure is standard in most Romance languages, and is very hard to shake.
And then there’s the outlier, like it’s raining cats and dogs. If you ask a native speaker to think of a weather-based idiom, it’s probably the first one they’ll think of. And it’s often the first one we teach learners too. But if you’re a native English speaker, think about how often you’ve used it, or heard anyone use it. For some reason we always think of it as a common phrase, but no-one actually uses it! I’m convinced it only exists in English-language classrooms.
So hopefully if you’re a native speaker you might have some insight into how frustrating learning English can be, and appreciate how well a non-native speaker is doing to be able to make themselves understood, even if what they say sounds a little funny every now and then.