No, the days you were in the US under a G-4 visa are not considered for the 5-year F-1 rule. Only prior stays under "F, " "J, " "M, " or "Q " visas are considered.
On an F-1 visa, you are exempt for 5 years, therefore you are still exempted in 2019 and will need to file a nonresident return (1040NR). You can use our partner Sprintax to file Form 1040NR,
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