argues that this approach is insufficient since it "forces one to analyze ... optional ... suffixes". Every verb has an obligatory inflection for person, number, and mood (all marked by a single suffix), and can have other inflectional suffixes such as tense, aspect, modality, and various suffixes carrying adverbial functions. Tense Tense marking is always optional. The only explicitly marked tense is the future tense. Past and present tense cannot be marked and are always implied. All verbs can be marked through adverbs to show relative time (using words such as "yesterday" or "tomorrow"). If neither of these markings is present, the verb can imply a past, present, or future tense. Aspect Marking aspect is optional in Iñupiaq verbs. Both North Slope and Malimiut Iñupiaq have a perfective versus imperfective distinction in aspect, along with other distinctions such as: frequentative (-ataq; "to repeatedly verb"), habitual (-suu; "to always, habitually verb"), inchoative (-łhiñaaq; "about to verb"), and intentional (-saġuma; "intend to verb"). The aspect suffix can be found after the verb root and before or within the obligatory person-number-mood suffix. Mood Iñupiaq has the following moods: Indicative, Interrogative, Imperative (positive, negative), Coordinative, and Conditional. Participles are sometimes classified as a mood. Indicative mood endings can be transitive or intransitive, as seen in the table below. Syntax Nearly all syntactic operations in the Malimiut dialect of Iñiupiaq—and Inuit languages and dialects in general—are carried out via morphological means."The language aligns to an ergative-absolutive case system, which is mainly shown through nominal case markings and verb agreement (see above). The basic word order is subject-object-verb. However, word order is flexible and both subject and/or object can be omitted. There is a tendency for the subject of a transitive verb (marked by the ergative case) to precede the object of the clause (marked by the absolutive case). There is likewise a tendency for the subject of an intransitive verb (marked by the absolutive case) to precede the verb. The subject of an intransitive verb and the object of a clause (both marked by the absolutive case) are usually found right before the verb. However, "this is [all] merely a tendency." Iñupiaq grammar also includes morphological passive, antipassive, causative and applicative. Noun incorporation Noun incorporation is a common phenomenon in Malimiutun Iñupiaq. The first type of noun incorporation is lexical compounding. Within this subset of noun incorporation, the noun, which represents an instrument, location, or