Is known as a relative or relativizer, specific past time, negative imperative, “again” imperative prepronominal prefix.
It appears a ts – (j -) before a vowel, tsi – (ji -) before a consonant or tsu – (ju -) before w.
It appears before any other prefix in a word, but cannot be used with the y – prefix (irrealis).
One of its main uses is to indicate that a verb is part of a relative clause. Remember from high school, a relative clause is a subordinate clause that modifies a noun, also called an adjectival clause.

It is translated to ‘who,’ ‘which,’ or ‘that.’

ᎠᎿᏬ ᏥᏍᎩᏅᏁᎸ ᏥᏖᏍᎦ / ahnawo tsisginvnelv tsitesga / ahnawo jisginvvneelv jiȉteesga – ᎠᎿᏬ ᏥᏍᎩᏅᏁᎸ ᏥᏖᏍᎦ is pronounced short a – aspirated n – short a – w – long o j – short i – s – g – short i n – nasalized uh (held and high tone) – n – long a – l – nasalized uh (high tone) j – short i (held and lowfall tone) – t – long a (held) – s – g – short a. ahnawo tsisginvnelv tsitesga means I’m ironing the shirt that you gave me. ahnawo = shirt; tsisginvnelv = that you gave me; tsitesga = I iron.

ᎠᏍᎦᏯ ᎦᏬᏂᎭ / asgaya gawoniha / asgaya gawoőniha – asgaya gawoniha is pronounced short a – s -g – short a – y – short a g – short a – w – long o (held, lowfall tone) – n – short i – h – short a. ᎠᏍᎦᏯ ᎦᏬᏂᎭ means a man is speaking (talking). asgaya = man gawoniha = he is speaking (talking). If we want to say a man who is speaking (talking) you would add the tsi before the ga in he is speaking (talking). It would look like asgaya tsigawoniha. 

ts- (j-) cannot occur on the same verb form with the ga- (meaning since). However, if can be attached to -igi in instances which the main verb is marked with ga-

Another function of ts- (j-) is to indicate specific past time.

It appears as ts- (j-) before vowels, tsi- (ji-) before consonants and tsu- (ju-) before w.

It is used in sentences which contain a reference to a definite time in the past. It is also prefixed to verb forms in sentences which do not contain an explicit time reference, if such a reference to a definite time in the past has been previously made and/or is understood by the speaker and listener.

ᎩᎳᏊ ᏥᎷᎦ / gilaquu tsiluga / kilagwu chiʔluuga – gilaquu tsiluga is pronounced k – short i – l – short a – gw – oo ch – short i – glottal stop (pause) – l – short u (held) g – short a. ᎩᎳᏊ ᏥᎷᎦ means you climbed it just a moment ago. gilaquu = just now tsiluga = you climbed it.

ᏦᎳ ᏥᏥᏁᎸᎢ / tsola tsitsinelvi / joola jijiȉneélvvʔi – ᏦᎳ ᏥᏥᏁᎸᎢ is pronounced j – long o (held) – l – short a j – short i – j – short i (held and low fall) – n – long a (held and rising tone) – l – nasalized uh (held and high tone) – glottal stop (pause) – long e. tsola tsitsinelvi means I gave him tobacco. tsola = tobacco tsitsinelvi = I gave him.

*As noted in the sentence above, ts- is required in sentences which reference to a specific past time is understood provided the past tense suffix (-vʔi) is used. This suffix indicates the speaker witnessed the action or state indicated by the verb form. It is also used with the reportative past tense suffix (-eʔi).

This relative prefix cannot be attached directly to a negated verb form. To make a negative relative you must add negative affixes n- / ni – / na – to the verb form. Then the relative ts- (j-) attaches to the auxiliary verb -igi = tsiigi. When this occurs the pitch changes. The second last syllable in the word becomes high tone.

ᎠᏍᎦᏯ ᏂᎪᏬᏂᏍᎬᎾ ᏥᎩ / asgaya nigowonisgvna tsigi / asgaya nigowoőnisgvna jígi – ᎠᏍᎦᏯ ᏂᎪᏬᏂᏍᎬᎾ ᏥᎩ is pronounced short a – s – g – short a – y – short a n – short i – g – long o w – long o (held and lowfall tone) – n – short i – s – g – nasalized uh (lowfall tone) – j – short i (high tone) – g – long e. asgaya nigowonisgvna tsigi means the man who isn’t speaking. asgaya = man nigowonisgvna = is not speaking (talking) tsigi = not who.

ts – (j -) is also used for the ‘again’ imperative.

It appears as ts – (j -) before vowels, tsi – (ji -) before consonants, and tsu – (j – ) before ‘w.’

When this prepronominal prefix is used for this purpose the vowel of the following syllable undergoes vowel lengthening (whether short or long) and tone change (typically rises). However, if that prefix is a vowel, there is a glottal stop between the two vowels. *Remember there is always a glottal stop between two vowels side by side.* It does not have to appear with siquu (again) to have that meaning.

ᏥᏣᏚᎦ / tsitsaduga / jiíjádúùga – tsitsaduga is pronounced j – short i (held, rising tone) – j – short a (high tone) – d – oo (held, falling tone) – g – short a. ᏥᏣᏚᎦ means throw it again. *Since the pitch and vowel lengthening changes when ts – (j -) prepronominal prefix is used for the purpose of ‘again’ to say throw it would be tsaduga / tsaduȕga (pronounced j – short a – d – oo (held and lowfall tone) – g – short a).*

ᏏᏊ ᏥᏂᎯᏫ / siquu tsinihiwi / siígwu jiiniíhiwi – ᏏᏊ ᏥᏂᎯᏫ is pronounced s – short i (held and rising tone) – gw – oo j – short i (held) – n – short i (held and rising tone) – h – short i – w – long e. siquu tsinihiwi means say it again.

One way of expressing ‘why’ questions is to start with gado (what) and then a ts – (j -) prepronominal prefixed verb.

ᎦᏙ ᏣᏠᎯᎭ / gado tsatlohiha / gado chadloohíha – ᎦᏙ ᏣᏠᎯᎭ is pronounced g – short a – d – long o ch – short a – dl – long o (held) – h – short i (high tone) – h – short a. gado tsatlohiha means why are you crying?

This prepronominal prefix can be used as a negative imperative, ‘again’ imperative and ‘why’ in addition to relative, relativizer, and specific past time.

When used as the negative imperative it appears as ts – (j -) before vowels, tsi – (ji -) before consonants and tsu – (ju-) before ‘w.’

In the negative imperative is can be used with Immediate and Completive verb stem commads:

ᏞᏍᏗ ᏤᏅᏂᎵ / tlesdi tsenvnili / hleȅsdi jénvvniȉli – tlesdi tsenvnili is pronounced aspirated l – long a (held, lowfall tone) – s – d – long e j – long a (high tone) – n – nasalized uh (held) – n short i (held, lowfall tone) – l – long e. ᏞᏍᏗ ᏤᏅᏂᎵ means let’s you and I not hit him.

ᏞᏍᏗ ᏥᏙᏣᏕᏏ / tlesdi tsidotsadesi / hleȅsdi jidoójádéesi – ᏞᏍᏗ ᏥᏙᏣᏕᏏ is pronounced aspirated l – long a (held and lowfall tone) – s – d – long e j – short a – d – long o (held and rising tone) – j – short a (high tone) – d – long a (held and high tone) – s – long e. tlesdi tsidotsadesi means don’t throw them.