English has very few inflections. Verbs only have a handful of forms (four in the case of regular verbs : play, plays, playing, played), and  - unlike all other European languages - articles and adjectives are invariable. This makes the basic grammar comparatively easy. If you were studying any other European language, you'd have to learn dozens of other inflections determined by number, gender and sometimes even grammatical case.

That's the plus. On the minus side, English, especially spoken English, is extremely idiomatic. This is why a foreign learner who has spent years studying English grammar and memorising lists of words can still fail to understand even the most basic native-speaker conversation.