"The foreigner next door moved out so I don't have as many opportunities to speak English."
"My neighbour from overseas has moved out so my chances to speak English have decreased."
"The foreigner next door moved out so I don't have as many opportunities to speak English."
"the foreigner" 「外人」
"next door" 「隣」
"moved out" 「引っ越した」
"so ~" 「なので〜」
"I don't have as many ~" 「〜少ない」・「〜が減った」
"opportunities" 「機会」
"to speak English" 「英語を話す」
"My neighbour from overseas has moved out so my chances to speak English have decreased."
"My [neighbour](https://eikaiwa.dmm.com/uknow/questions/39319/)" 「お隣さん」
"from overseas" 「外国から来た」
"has moved out" 「引っ越した」
"my chances ~" 「私の〜機会」
"have decreased" 「減った」
The foreigner who used to live next to me moved away, so I don't have as many opportunities to speak English these days.
There was a Canadian who lived next door to me, but he moved somewhere else, so I haven't had as many chances to speak English since he moved.
この場合、次のように言うと良いでしょう。
ーThe foreigner who used to live next to me moved away, so I don't have as many opportunities to speak English these days.
「隣に住んでいた外国人が引っ越したので、最近英語を話す機会が減った」
I don't have as many opportunities to ... で「…する機会が減った」
ーThere was a Canadian who lived next door to me, but he moved somewhere else, so I haven't had as many chances to speak English since he moved.
「私の隣にカナダ人が住んでいたが、どこかに引っ越したので、彼が引っ越して以来、英語を話すチャンスが減った」
I haven't had as many chances to ... で「…するチャンスが減った」
ご参考まで！
オーストラリア 
カナダ 
