Instrumental case answers the questions КЕМЛЕ? (with whom, by whom), НЕЛЕ? (by means of what/ by use of what). It marks the means by which the action is done, for example, “to go by bus”, “to hear with the ears”. It represents the instrument that is used to carry out the action: калбакла by spoon, кӱреклеby a shovel, коллоby hand, бычаклаby knife.

It also shows the means of movement. Have a look at examples: кемелеby boat, машиналаby car.

To form the Instrumental case you add affixes -ЛА, -ЛЕ, -ЛО, -ЛӦ to the root form of the noun and personal pronoun.

Here we follow only the Vowel harmony – look at the last syllable of the noun root. It doesn’t matter what consonant the word ends in – anyway all the affixes begin with the consonant (л).
When you see a hard vowel (а, у, ы) in the last syllable, add –ЛА: талайлаby sea, тараклаby comb, чайлаwith tea/be tea.
Аnd if there is (o) add –ЛО: отлоby fire/with fire.

When you see a soft vowel (е, и, ӱ), add affix –ЛЕ, for instance: кемелеby boat, темирлеby iron/with iron.
And add –ЛӦ after the vowel (ӧ) which is in the last syllable, like in: кӧслӧwith eyes, сӧслӧby use of words, кӧнӧклӧby means of a bucket.

The instrumental case also indicates a person together with someone did something, and often the noun or pronoun is accompanied by the word КОЖО (together with): улусла кожоtogether with people, балала кожо together with a child. Бисле кожо кем барар? – Who will go with us? Mен телевизорло кино кӧрӧримI will see a movie on TV. Meн слерле кожо артарым I will stay with you.

The instrumental case in Altai language can also indicate the place of movement: суулаby river/across the river, кӧллӧby lake, јаратлаdown by the riverside, кырлаby mountain.

Note that the affixes -ЛА, -ЛӦ, -ЛО, -ЛЕ are not stressed. If you put the word stress on these affixes you will change the noun into the imperative verb which was formed from a noun.
Compare: малтаax/wood chopper
малтала [maltala] – by the wood chopper
малтала [maltala]– ax (imperative verb)
чайла [tʃaila] – with tea
чайла [tʃaila ]– have a tea (imperative verb).
So don’t put the word stress on these affixes please.

The personal pronouns in instrumental case

When the pronouns мен (I), сен (you (singular) add the affixes of Instrumental case they also add the letter [и] before the affix, so they become: менилеwith me/by me, сенилеwith you/by you. Notice, that the pronoun ол (he/she/it) changes its consonant and adds (ы) before the affix –ЛА: он+ы+лаby him.

Nominative      Instrumental
мен    I мениле    by me/with me
сен   you сениле    by you/with you
ол     he/she/it оныла     by him/with him
бис   we бисле    by us/with us
слер    you слерле   by you (pl)/with you
олор    they олорло   by them/with them