determined, strong' < *derbaną 'to work', Proto-Baltic *derṷā and Proto-Germanic *terwą, meaning 'tar, resin', Proto-Baltic *gāmurii̯as and Proto-Germanic *gōmô, meaning 'palate'. Baltic and Germanic languages also share numeral formation for 11 to 19, both partially possess the same formation of verbs in past tense (ablaut), absence of the aorist. According to German linguist Wolfgang P. Schmid, at first Proto-Baltic was a centum language along with Proto-Germanic, but it eventually became satem later on. Some scholars believe that Baltic and Germanic contacts are older than those with Slavic languages while others claim the opposite. According to Lithuanian linguist Saulius Ambrazas, Germanic people borrowed certain suffixes from their Baltic neighbours, such as *-ing-, *-isko-, *-ō-men- (e. g., Old High German: arming 'poor person', Old Icelandic: bernska 'childhood', Gothic: aldōmin (dat.) 'senility'). Phonetics and phonology Vowels and diphthongs The vowels of Proto-Baltic changed little in comparison to PIE: short vowels *a and *o coincided into a single *a while the reduced Indo-European primary vowel schwa (*ə) also turned into *a as it did in other Indo-European languages of Europe and it ceased to exist in the middle of words. According to the proponents of the Laryngeal theory, the primary schwa appeared by turning laryngeals into vowels, which makes its reconstruction for PIE unnecessary and obsolete. There were four short and five long vowels as well as four short and six long diphthongs as presented below: Vowels *a, *e, *i, *u together with semivowels *r, *l, *m, *n of Proto-Baltic were used to form mixed diphthongs as they are being used in the modern Baltic languages today. It is also well known that there were mixed diphthongs with long vowels at the endings. Long diphthongs can be reconstructed when glottaling (e. g., PIE: *pl̥h₁nós 'full' > Proto-Baltic: *pī́ˀlnas 'full'), compared to PIE, the position of stress in the example is conditioned by Hirt's law. Long mixed diphthongs, which position in the morpheme is hardly determined or their existence is questionable are presented in Italic: Consonants The consonants of Proto-Baltic experienced greater changes than primary vowels when in their primordial condition. PIE aspirated and labialized velar consonants (*bʰ, *dʰ, *gʰ, *gu̯, *gu̯ʰ, *ku̯) in Proto-Baltic coincided with plain consonants (*b, *d, *g, *k) as they did in some other Indo-European languages. However, at the early stages of development, the differences between plain and aspirated voiced plosives might have been retained. This is because before the