along with what RelevantApricot said, it may be helpful to check the kanji too. personally seeing the kana change 使う -> 使います is easier to understand for me than thinking of the sounds sometimes, like 会う -> 会います -> 会った
When conjugating a verb, you change the last kana. You shift the kana (‘う’ in this case) to it’s equivalent row ‘い’ sound (which is also ’い’ in this case) and add the helper verb ます.
3 comments
because you take the last u-sounding and replace it with the same i-sounding.
つかう -> u turns to i -> つかいます
かく-> ku turns to ki -> かきます
There’s the easy question thread for questions like this btw: https://www.reddit.com/r/LearnJapanese/comments/zhd41r/daily_thread_simple_questions_comments_that_dont/
along with what RelevantApricot said, it may be helpful to check the kanji too. personally seeing the kana change 使う -> 使います is easier to understand for me than thinking of the sounds sometimes, like 会う -> 会います -> 会った
When conjugating a verb, you change the last kana. You shift the kana (‘う’ in this case) to it’s equivalent row ‘い’ sound (which is also ’い’ in this case) and add the helper verb ます.