sjá

From Old Norse séa, sjá, from Proto-Germanic *sehwaną, from Proto-Indo-European *sekʷ- (“to see, notice”).

• IPA^(key): /ˈsjauː/

  Rhymes: -auː

sjá (strong verb, third-person singular past indicative sá, third-person plural past indicative sáu, supine séð)

1. to see, to sense or perceive with one's eyes

   Sérðu illa? — Nei, ég sé mjög vel.

   Have you got bad eyesight? — No, I see very well.

2. to see, to perceive, to spot
3. to see, to understand

   Þú hlýtur að sjá hvað þetta er asnaleg hugmynd!

   You must see what a stupid idea this is!

• (spot): koma auga á
• (understand): skilja, botna í

From earlier sási (attested in runic insriptions), originally the normal declension of sá + -si. Cognate with Old English þes (English this), Old High German dese (German diese).

• þessi

sjá (neuter þetta)

1. (demonstrative) this, that (referring to both persons and things)

• Icelandic: þessi m or f, þetta n
• Faroese: hesin m, henda f, hetta n
• Norwegian Nynorsk: denne m or f (-nn- from the accusative), dette n, desse pl
• Old Swedish: þænni
  • Swedish: denna c, detta n, dessa pl
• Danish: denne c, dette n, disse pl
  • Norwegian Bokmål: denne c, dette n, disse pl

From Proto-Germanic *sehwaną (“to see”) (for cognates see there). Ultimately from Proto-Indo-European *sekʷ- (“to see, notice”).

• séa, siá

sjá (singular past indicative sá, plural past indicative ságu, sá, past participle sénn)

1. to see

• sjón f, sýn f (“sight”)

• sjá in A Concise Dictionary of Old Icelandic, G. T. Zoëga, Clarendon Press, 1910, at Internet Archive.

See the etymology of the corresponding lemma form.

sjá

1. first-person singular present active subjunctive of vera

• Old English and its relatives, Google books
• Ragnvald Iversen, Norrøn grammatikk, 6th edition, 1961.