Learn English – How should I use “any” in “if clauses”

1. Are you hearing that noise?
2. That cake is tasting delicious.
3. You are smelling like a rose.
4. He is seeing the blue sky.

All of the above sentences would be considered as being either ungrammatical or nonstandard English by most prescriptive grammar books. And I would avoid saying these type of phrases myself. Furthermore, it is true that verbs of senses are not normally used in the present progressive but I've never read a grammar book which strictly prohibited their use. Sentences 1 to 4 will sound more natural and "native-like" if the present simple tense is employed.

1. Can you hear that noise?
2. That cake tastes delicious.
3. You smell like a rose.
4. He can see the blue sky.

The verb hear often means we perceive or detect a sound with our ears. It is not a dynamic action but an involuntary one, hence it is classed as being a stative verb. On the other hand, the verb listen expresses intention and is a dynamic verb. Consider:

A: What are you listening to?
B: This great album by [group], I'm always listening to their music.

You couldn't replace listen with hear in that particular context.

To express the concept that a noise is audible with your ears, we often use the modal verb, can in the present tense.

(Three friends on Skype)
A: Can you hear me, now?
B: Yes, I can hear you loud and clear.
C: No, sorry. I can't. It's very difficult to make out what you're saying. The audio's not very good I'm afraid.

Wikipedia confirms and adds

Verbs of mental state, sense perception and similar (know, believe, want, think, see, hear, need, etc.) are generally used without progressive aspect, although some of them can be used in the progressive to imply an ongoing, often temporary situation (I am feeling lonely), or an activity (I am thinking about a problem). (...) In colloquial English it is common to use can see, can hear for the present tense of see, hear, etc.

However, the verb hear also means to receive information by the ear, as Ws2's answer illustrates, and in this case the progressive form can be used e.g.,

• I'm constantly hearing stories about those awful people who've recently moved in the neighbourhood. They say, the son is an ex-convict.
• I am constantly hearing about sugar and how it is truly evil (...).
• This is the first time I'm hearing this.

and in the phrase quoted by the OP

"Are you hearing enough complaints?" = Have you been receiving information recently?

^{Feel in my opinion, does not fit very well in the category of stative verbs. Feel when it is a sense can be used in the progressive form as much as the present simple tense. 1) I'm feeling lazy today (I feel lazy today) 2) How are you feeling? (How do you feel?) 3) He's not feeling too well. (He doesn't feel too well.) BUT 4) What are you doing? I'm feeling this textile (I feel this textile.).}

I can use the continuous tense in the following without any fear of sounding odd: "I'm smelling this milk to see if it's any good", "What are you tasting?"; "The sniffer-dog is smelling all the suitcases for explosives" (as suggested by Ws2); and "I'm seeing Anthony later tonight."

Michael Swan in Practical English Usage gives a list and definition of these stative verbs.

There are many verbs that are not usually used in the progressive tenses and others that are not used in the progressive tenses in certain of their meanings. The most important of these [stative] verbs are:

1. dislike, hate, like, love, prefer, want, wish
2. astonish, impress, please, satisfy, surprise
3. believe, doubt, feel (=have an opinion), guess, imagine, know, mean, realize, recognize, remember, suppose, think (=have an opinion), understand
4. hear, see, measure (=have length etc), taste (=have a flavour), smell (=give out a smell), sound, weigh (= have weight)
5. belong to, concern, consist of, contain, depend on, deserve, fit, include, involve, lack, matter, need, owe, own, possess
6. appear, resemble, seem

So to summarise, it is not true that the verbs, hear, see, taste, etc. are not used in the continuous forms, it depends on context and meaning.

The Oxford Dictionary Online (a proper noun) defines proper noun as

A name used for an individual person, place, or organization, spelled with initial capital letters, e.g., Larry, Mexico, and Boston Red Sox. Often contrasted with common noun.

[It also conflates proper nouns with proper names, and I will not try to sort that our in this answer.]

As the questioner suggests, Wikipedia defines it as

a noun that in its primary application refers to a unique entity, such as London, Jupiter, Sarah, or Microsoft, as distinguished from a common noun, which usually refers to a class of entities (city, planet, person, corporation), or non-unique instances of a certain class (a city, another planet, these persons, our corporation).

I disagree with the criterion of unique. Rather, a proper noun refers to a specific instance of something. During the bestowing of a proper noun, the naming entity seeks to distinguish the individual accorded the proper noun from others in the generic class. When my father named me Dopey, he sought to distinguish me from my brothers, Bashful and Doc, and whoever else might come along later. He didn't especially care that Mrs. McGillicutty, three streets over, had also named her son Dopey. Within our circle, Dopey meant me.

There are very few proper nouns that are truly unique. The number of towns named Springfield, Madison, and Franklin are in the dozens apiece. However jurisdictions resist identical names within their purview. A town near me was named Marion and was called that for decades before someone in the state realized there was another town of the same name and our neighbor was rechristened East Marion.

If it were just me and Dad on a desert island, naming me Boy might work just fine. And maybe if only I were in the room and he said Now listen to me, Son, that would be okay. But when he yelled up the stairs, son, all his kids responded or no one did.

To each of us, Dad means the specific Dad (or sometimes Dads) that relate most closely to us. I had a mother and a stepmother, both of whom I called Mom. I can speak of my two moms, but when I address them or use them without a limiter (such as my mom), I refer to them in the capital.

To sum up, things that are virtually never grouped into a class and have been named to be specific within their own circle are always captialized, even when they are artificially aggregated.

• All the Alberts in the class should stand.
• There are many Washingtons in the US.

These retain their upper case status even when they are converted to a category with a modifier

• The Microsofts of the world will have to rethink their strategies.
• The Roosevelts were a political and social force to be reckoned with.

But common nouns that are used as a term of address or in lieu of a name without modifier are capitalized in those circumstances, but lower case in others. So

• I asked my mother to come over.
• I asked Mother to come over.