I noticed that the first three digit words for most Austronesian languages are awfully close to P.I.E. I speak Tagalog and at first, I had thought that the words for one two and three had been taken from Spanish, (Isa, Dalawa, Tatlo) but when I went to look at the Austronesian Languages page on Wikipedia, I was baffled to see that they had been so close to P.I.E. Why is this so?
Linguists have noticed this similarity, and it is not just a one-off case like another answer seems to suggest. Quoting from Shrikant Talageri's blog:
Isidore Dyen, in a paper presented in 1966 and published in 1970, makes out a case showing the similarities between many basic words reconstructed in the proto-Indo-European and proto-Austronesian languages, including such basic words as the first four numerals, many of the personal pronouns, and the words for "water" and "land". And Dyen points out that "the number of comparisons could be increased at least slightly, perhaps even substantially, without a severe loss of quality" (DYEN 1970:439).
• a) The very first four numerals: Proto-Indo-European (*sem, *dwōu/*dwai, *tri, *qwetwor) and Proto- Austronesian (*esa, *dewha, *telu, *pati/*epati).
• Compare Tocharian sas/se 'one', Romanian patru 'four', Welsh pedwar 'four' and Malay sa/satu 'one', epat 'four'. [Malay dua 'two' and tiga 'three' require no comparison].
• b) Personal Pronouns: I, we, you, he/she/it, (demonstr.) this/he: PIE *eĝh, *ṅsme, *yu, *eyo/*eya, *to/*eno. PA *aku, Tagalog ka-mi, Tagalog ka-yo, PA *ia, *itu/inu.
• c) "Land" and "water": PIE *wer, *ters. PA *wair and *darat (Sanskrit vāri and dharā).
[EDIT: vāri (वारि) = water and dharā (धरा) = land. Clarifying this because the quoted text gives the opposite (and wrong) impression.]
The author of the blog subscribes to the out-of-India theory (OIT), in which India is the homeland of PIE. That makes any contact between PIE and Proto-Austronesian a reasonable consequence.