(_a_). It is also frequently used instead of a possessive pronoun in speaking of one's own relatives, or when there is no doubt as to the person to whom the article la refers.
Examples.--_Mi amas la patron_ = I love my (the) father. _Iru al la patrino_ = Go to your (the) mother. _Kie estas la kuzo?_ = Where is your (the) cousin? _La patro staras apud la filo_ = The father stands by (at the side of) his (the) son.
101. The article is almost always used before numeral adjectives showing the day, hour, month, etc., when these nouns are understood.
Example.--_Hodiaŭ estas la dudek-sepa (tago) de Marto_ = To-day is the 27th of March.
(_a_). Its use is optional before the names of the seasons, and also before each separate noun or adjective.
Examples.--_En la vintro_, or, _En vintro_ = In the winter. _En la somero_, or, _En somero_ = In the summer. _La arboj, la floroj kaj la kreskaĵoj de la ĝardeno_ (or, _La arboj, floroj kaj kreskaĵoj_) = The trees, (the) flowers and (the) plants of the garden.
(_b_). It is not generally used after ĉiuj = _all_, or, _all the_.
Example.--_Mi ne vidis ĉiujn arbojn en la ĝardeno_ = I did not see all the trees in the garden.
(_c_). It is not used after da (see par. 259).
N.B.--From the foregoing remarks it will be seen that the English student will have no difficulty in the use of the article, if he be careful to use it with words defining a _class_ or the _totality_ of persons or things. He will get a good idea of its use if he will carefully study the first few exercises in the "Ekzercaro," or Exercises 1 to 4 in Part III.
In case of doubt whether the article should be used or not, it is better to omit it.
102. Elision.--The final _A_ of the article may be omitted in certain cases (see par. 56 and Rule 16, par. 94).
103. A noun (in the singular number) in all its cases, except the accusative, ends in _-O_. The accusative is formed by the addition of _N_. In the plural it ends in _-OJ_, and the accusative plural is formed by adding _N_ to these letters. Thus the root arb- is made into a noun with its numbers and cases as follows:--
Arb-o = _a tree_ (nominative, singular). Arb-on = _a tree_ (accusative, singular). Arb-oj = _trees_ (nominative, plural). Arb-ojn = _trees_ (accusative, plural).