Comparative and Adjectival Phrases: What is Richer, Heavier and More Sound Problem: Russian and English both have morphological and analytical comparatives (MC and AC respectively), (1). The major factors that influence the ability to derive an MC are: i) prosody (the number of syllables, valid only for English), ii) phonotactics, and iii) morphonology (sensitivity to deverbal and other recategorizing affixation on adjectives), (2). Then, English can use MC attributively whereas Russian can not, (3). Attributive ACs are ok in both languages, (4). Both languages exhibit the constraint on the use of any complements ("object of comparison") and/or adjuncts ("experiencer") to prepositional attributive comparatives, (5). (The postpositional use of DegPs with complements is grammatical in both languages, (6)). Finally, prenominal ACs in Russian allow for complementation, (7). Questions: 1. What kind of constraints delimits the derivation of comparatives? 2. Why MCs can be used prenominally in English, but not in Russian? 3. Why prenominal attributive ACs are grammatical in both languages? 4. Why Russian prenominal attributive comparatives (ACs) can take complements whereas English ones can not? Structures: We suppose that a comparative can belong to one of the two types of constituents: MCs are instances of some Deg(ree) Phrases headed by the degree affix, whereas ACs are ordinary APs with the degree marker (more) in Spec, AP. A head of DegP is filled via Merge of some adjectival item which can be either i) taken from the Lexicon or b) created as a result of some syntactic process, i.e. the attachment of some (category marking) affixes. Analysis: The answer on 1: The degree affixes in the Deg head impose two kinds of constraints on the item which it is combined with. The first constraint is pure phonological (prosody and phonotactics) but the second one deals with syntax and can be articulated as follows: Deg-heads (-er / -eje) can Merge with some item iff it has the [+Adj] feature and if it is borrowed directly from the Lexicon (Lexical Adjective Condition, LAC) [+Adj] feature is either an inherent property of a stem or is assigned by some lexical-level affix (-y, -le,... / -n, -k,...). Apart of these affixes there is another group of [+Adj] morphemes (-ful, -ish,... / -vs, -esk,...) that are attached post-lexically. Either the unmarked stems or stems with lexical-level affixes can feed the Deg head. Adjectives derived post-lexically (syntactically) can not. Both Russian and English display LAC. See the table (8). The answer on 2: The main condition on any prenominal attributive modifier in Russian is that it must agree with the head nominal in case, number and gender. But the DegP head lacks concord features. Hence constraint on the attributive use of MC follows. English has no DP-internal concord and so nothing prevents Deg(P)s from being used attributively. The answer on 3: ACs in Russian and English are instances of AP, which can put an adjectival item (no matter lexically or syntactically derived) in the head position and a degree word in Spec, (9). Russian ACs can be used prenominally, since the adjective in the AP head position bears all necessary concord features as well as heads of other modifier phrases do. The answer on 4: English attributive adjectives are heads, not phrases. Russian, but not English can use adjectival phrases for the (pre-)nominal attributive modification. This can be seen by different behaviour of positive degrees in both languages, (10). Extensions: In what follows we consider in more detail phonological, syntactic and lexical aspects of comparatives in both languages, for instance, formation of adjectival lexical items by affixes