<!doctype html><meta charset=utf-8><meta name=viewport content='width=device-width,initial-scale=1'><title>Past Tense Practice</title><style>body{font-family:-apple-system,Arial;background:#08111f;color:#fff;margin:0}main{max-width:650px;margin:auto;padding:14px}h1{text-align:center}nav{position:sticky;top:0;background:#08111fee;padding:8px 0;z-index:2}select,button{font:inherit}select{width:100%;padding:12px;border-radius:12px;background:#14213a;color:#fff;border:1px solid #345}.q{background:#111b2b;border:1px solid #2b3b55;border-radius:18px;padding:16px;margin:12px 0}.q h3{margin:0 0 12px;font-size:18px}.o{display:block;width:100%;text-align:left;margin:8px 0;padding:13px;border:1px solid #345;border-radius:12px;background:#0b1422;color:#fff}.good{border-color:#2c6!important;background:#123b26!important}.bad{border-color:#e55!important;background:#3b171b!important}.fb{padding:10px;border-radius:10px;margin-top:8px;background:#17243a}.top{font-size:13px;color:#9fb0c8}.res{text-align:center;font-size:28px;font-weight:800;padding:16px}.bar{height:7px;background:#16233a;border-radius:9px;overflow:hidden}.bar i{display:block;height:100%;background:#55dff5;width:0}</style><main><h1>Past Tense Practice</h1><p class=top>10 exámenes · 20 preguntas · Was/Were · verbos regulares/irregulares · Did/Didn't</p><nav><select id=e></select><p id=m class=top></p><div class=bar><i id=b></i></div></nav><section id=x></section><button id=r>Reiniciar examen</button><div id=z class=res></div></main><script>let V=[['work','worked'],['play','played'],['watch','watched'],['study','studied'],['cry','cried'],['stop','stopped'],['hug','hugged'],['go','went'],['eat','ate'],['buy','bought'],['think','thought'],['teach','taught'],['begin','began'],['drink','drank'],['run','ran'],['do','did'],['have','had'],['see','saw']],T=[['She','was','were'],['He','was','were'],['It','was','were'],['I','was','were'],['You','were','was'],['We','were','was'],['They','were','was']],D=[['She','go','went'],['They','eat','ate'],['He','play','played'],['We','watch','watched'],['I','study','studied']],A=Array.from({length:10},()=>Array(20)),L=Array.from({length:10},()=>Array(20).fill(0)),c=0,$=i=>document.getElementById(i),e=$('e'),x=$('x');for(let i=0;i<10;i++)e.add(new Option('Examen '+(i+1),i));function rnd(a){return a[Math.floor(Math.random()*a.length)]}function q(n){let k=n%4;if(k==0){let t=rnd(T);return[t[0]+' ___ happy yesterday.',[t[1],t[2],'did','is'],0,'Con '+t[0]+' usamos '+t[1]+' en pasado.']}if(k==1){let v=rnd(V),g=v[1].endsWith('ed');return['Past of "'+v[0]+'":',[v[1],v[0],v[0]+'ed','did '+v[1]],0,(g?'Verbo regular: ':'Verbo irregular: ')+v[0]+' → '+v[1]+'.']}if(k==2){let d=rnd(D);return["Choose the correct negative sentence.",[d[0]+" didn't "+d[1]+'.',d[0]+" didn't "+d[2]+'.',d[0]+' wasn\'t '+d[1]+'.',d[0]+' not '+d[2]+'.'],0,"Después de didn't, el verbo va en forma base: "+d[1]+'.']}let d=rnd(D);return['Choose the correct question.',['Did '+d[0].toLowerCase()+' '+d[1]+'?','Did '+d[0].toLowerCase()+' '+d[2]+'?','Was '+d[0].toLowerCase()+' '+d[1]+'?','Were '+d[0].toLowerCase()+' '+d[2]+'?'],0,'Después de Did, el verbo va en forma base: '+d[1]+'.']}function render(){c=+e.value;x.innerHTML='';let done=0,ok=0;for(let i=0;i<20;i++){if(!A[c][i])A[c][i]=q(i+c);let a=A[c][i],d=document.createElement('div');d.className='q';d.innerHTML='<div class=top>Pregunta '+(i+1)+'/20</div><h3>'+a[0]+'</h3>';a[1].forEach((o,j)=>{let bt=document.createElement('button');bt.className='o';bt.textContent='ABCD'[j]+'. '+o;if(L[c][i]){bt.disabled=1;if(j==a[2])bt.classList.add('good');if(L[c][i]-1==j&&j!=a[2])bt.classList.add('bad')}bt.onclick=()=>{L[c][i]=j+1;render();document.querySelectorAll('.q')[i].scrollIntoView({behavior:'smooth',block:'center'})};d.appendChild(bt)});if(L[c][i]){done++;if(L[c][i]-1==a[2])ok++;let f=document.createElement('div');f.className='fb';f.textContent=(L[c][i]-1==a[2]?'✅ ':'❌ ')+a[3];d.appendChild(f)}x.appendChild(d)}$('m').textContent=done+' de 20 respondidas';$('b').style.width=done*5+'%';$('z').textContent=done==20?'Resultado: '+ok+'/20':''}e.onchange=render;$('r').onclick=()=>{A[c]=Array(20);L[c]=Array(20).fill(0);render()};render();</script>