Note: It’s not fair to say that English perfectly distinguishes singular and plural forms, though. After all, we have words like “fish” and deer” that are both. So, thinking about how we overcome such ambiguity in English with these words may help you understand what is going on in Japanese.
Overall, there are several methods of pluralization or structures resembling pluralization in Japanese. Consider the following:
This lesson will focus on ～たち as it is arguably the most difficult to master as its necessity is also something that is not straightforward. If it were simply a plural marker, we could just end there, but it isn't.
Historically, ～たち started out as a suffix for the nobility and the gods, but from this historical note alone, we know that it has never been just for simple pluralization purposes. In fact, when it is used today, whether it is used with nouns of living things or non-living things, it is OK not to use it. However, using ～たち often shows a sense of empathy.
Four men were shot and taken to the hospital.
A lot of interesting people attended the physics convention.
In Austin, the state capital of Texas, there are many homeless people.
In the next set of sentences, though, ～たち is not optional.
We have gathered this year as well from all over the country.
Ikeda and his group of three have a strong common bond.
I can't live on without you all.
The plural meanings of these phrases cannot be supplemented by the basic phrases themselves without ～たち. For phrases like 池田さんたち, one is no longer just using a typical third person pronoun phrase, but as Makino (1996) has stated, but a part of one's 'uchi'. Thus, the term ウチ人称 becomes appropriate.
We continue to see that an emphatic role is present in ～たち’s use. It may be clearly obligatory with pronouns, but why? Is it because we have a keen emotional awareness towards the number of pronouns? This is likely the case, and this factor appears to be what controls when ～たち is used regardless of what kind of noun is being used.
Now it's time to look at example sentences. To be fair and objective, all example sentences will be from Google searches. The reason for this is that example phrases in isolation may be deemed ungrammatical without context, and native speakers themselves may not agree with whether any given expression is used or not.
These trees which have awoken from a 30 year slumber
Those roses which have bloomed in the corner will also surely fade away.
The stars far away will shine despite being not being known by anyone.
Look at the expressions of cherry blossoms I took from various places at my home place, Kyoto.
The deer in Nara Park have boldly taken over the roads!
To the temple of foxes
This is a story about the resistance and defeat of the tanuki.
A group of cats have arrived.
The sparrows began to cry at once.
I took pictures of the chickens at my home.
We call birds who come to reproduce in the spring “summer birds”.
The cicadas are dying.
The fireflies caught up in the gale wind are raining down like a mist of light.
The coy fish in the pond are swimming lively.
You can watch the fish to one’s heart’s desire as you drink high class sake.
Group of clouds which resemble a painting
These memories which I wish would melt and disappear like this snow.
A lot of other nouns may require a lot of personification to work. A built-up sense of empathy is needed in such a situation.
25. あたしが大好きな本たちを紹介しますわ。 A bookworm may say this.
I'm going to introduce you to my precious books!
参照文献：認知世界の窓としての日本語の複数標示‐たち by 牧野成一