柯林斯英漢雙解詞典對兩個單詞的解釋：
兩個詞都可做名詞，可作動詞。
名詞釋義有天差地別，沒有可比性：
blockn. 大塊；大樓；街區；積木；壹大疊 (壹次大量購買的入場券、股票等)；?(思維、記憶等的) 阻滯
tacklen.?擒抱撞倒，阻截；(尤指釣魚等活動的) 器具-如：fishing tacke漁具
動詞釋義有重疊（都可以指阻擋），值得研究：
以下是精簡版總結：
blockv.阻塞/封鎖（道路，通道等）；擋住（某人的視野，某人的路等）；阻止（事情的發生等）
tacklev.阻擋（(美式或英式橄欖比賽中) 擒抱摔倒; (足球運動或曲棍球運動中) 搶斷）；處理/解決（麻煩，棘手的問題等）；坦率地與某人交談（以改變或完成某事）；攻擊（某人）
總結：
當兩個詞都用來表示阻擋時：
block可以指各種各樣的阻塞，阻止，擋住；
tackle只能指球賽中術語的搶斷等；最常用的意思還是處理（問題等），和deal with意思相近。
以下是動詞釋義-英漢雙解帶例句版-詳解：
block/blɒk/?CET4 TEM4?(blocking,blocked,blocks)
(1) V-T?To?block?a road, channel, or pipe means to put an object across it or in it so that nothing can pass through it or along it. 阻塞（通道等）， 封鎖（道路，海峽等）不使通過
例：Some students today blocked a main road that cuts through the centre of the city.壹些學生今天封鎖了穿過市中心的公路。
(2) V-T?If something?blocks?your view, it prevents you from seeing something because it is between you and that thing. 擋住（視野等）
例：...a row of spruce trees that blocked his view of the long north slope of the mountain.…擋住了他看向山北長坡視線的壹排雲杉。
(3) V-T?If you?block?someone's way, you prevent them from going somewhere or entering a place by standing in front of them. 阻擋（某人的路）
例：I started to move around him, but he blocked my way.我開始繞開他走，但他擋著我的路。
(4) V-T?If you?block?something that is being arranged, you prevent it from being done. 阻止（某安排，某事情發生等）
例：For years the country has tried to block imports of various cheap foreign products.多年以來，這個國家曾試圖阻止多種外國廉價產品的進口。
tackle/ˈtækəl/?CET4 TEM4?(tackling,tackled,tackles)
(1) V-T?If you?tackle?a difficult problem or task, you deal with it in a very determined or efficient way. 處理/解決（麻煩，棘手的問題等）
例：The first reason to tackle these problems is to save children's lives. 解決這些問題的首要原因是為了挽救孩子們的生命。
(2) V-T?If you?tackle?someone in a game such as American football or rugby, you knock them to the ground. If you?tackle?someone in soccer or hockey, you try to take the ball away from them. 球賽術語--(美式或英式橄欖比賽中) 擒抱摔倒; (足球運動或曲棍球運動中) 搶斷
例：Foley tackled the quarterback.福利擒住並摔倒了四分衛。
(3) V-T?If you?tackle?someone about a particular matter, you speak to them honestly about it, usually in order to get it changed or done. 坦率地與某人交談（以改變或完成某事）
例：I tackled him about how anyone could live amidst so much poverty. 我坦率地與他談論哪有人能在如此的極度貧困中生活。
(4) V-T?If you?tackle?someone, you attack them and fight them. 攻擊（某人）
例：Two security guards tackled and apprehended a man suspected of robbing 17 banks.兩名保安與壹名涉嫌搶劫17家銀行的男子搏鬥並逮捕了他。